diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6091cf7f4..ccafc0383 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Changed
 
 - Improved error handling when a room requires an access code but none was provided ([#3035])
+- Improved 404 error messages for better readability and clarity ([#86], [#3036])
+- Standardized 404 error handling on admin pages ([#1676], [#3036])
+- Improved and standardized room not found error handling in the room view ([#3036])
 
 ## [v4.14.2] - 2026-04-10
 
@@ -544,6 +547,7 @@ You can find the changelog for older versions there [here](https://github.com/TH
 [#31]: https://github.com/THM-Health/PILOS/issues/31
 [#75]: https://github.com/THM-Health/PILOS/issues/75
 [#77]: https://github.com/THM-Health/PILOS/issues/77
+[#86]: https://github.com/THM-Health/PILOS/issues/86
 [#300]: https://github.com/THM-Health/PILOS/issues/300
 [#315]: https://github.com/THM-Health/PILOS/issues/315
 [#372]: https://github.com/THM-Health/PILOS/issues/372
@@ -640,6 +644,7 @@ You can find the changelog for older versions there [here](https://github.com/TH
 [#1636]: https://github.com/THM-Health/PILOS/issues/1636
 [#1651]: https://github.com/THM-Health/PILOS/issues/1651
 [#1675]: https://github.com/THM-Health/PILOS/issues/1675
+[#1676]: https://github.com/THM-Health/PILOS/issues/1676
 [#1677]: https://github.com/THM-Health/PILOS/issues/1677
 [#1678]: https://github.com/THM-Health/PILOS/pull/1678
 [#1679]: https://github.com/THM-Health/PILOS/issues/1679
@@ -774,6 +779,7 @@ You can find the changelog for older versions there [here](https://github.com/TH
 [#3028]: https://github.com/THM-Health/PILOS/issues/3028
 [#3029]: https://github.com/THM-Health/PILOS/pull/3029
 [#3035]: https://github.com/THM-Health/PILOS/pull/3035
+[#3036]: https://github.com/THM-Health/PILOS/pull/3036
 [#3039]: https://github.com/THM-Health/PILOS/issues/3039
 [#3040]: https://github.com/THM-Health/PILOS/pull/3040
 [unreleased]: https://github.com/THM-Health/PILOS/compare/v4.14.2...develop
diff --git a/app/Exceptions/Handler.php b/app/Exceptions/Handler.php
index f100a15d8..a57133302 100644
--- a/app/Exceptions/Handler.php
+++ b/app/Exceptions/Handler.php
@@ -4,12 +4,15 @@
 
 namespace App\Exceptions;
 
+use Illuminate\Database\Eloquent\ModelNotFoundException;
 use Illuminate\Foundation\Exceptions\Handler as ExceptionHandler;
 use Illuminate\Foundation\ViteException;
 use Illuminate\Http\Request;
 use Illuminate\Support\Facades\Log;
+use Illuminate\Support\Str;
 use Psr\Log\LogLevel;
 use Spatie\LaravelIgnition\Exceptions\ViewException;
+use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
 use Throwable;
 
 class Handler extends ExceptionHandler
@@ -77,5 +80,21 @@ public function register(): void
 
             return null;
         });
+
+        $this->renderable(function (NotFoundHttpException $e, Request $request) {
+            if ($request->expectsJson()) {
+                $modelNotFoundException = $e->getPrevious() instanceof ModelNotFoundException ? $e->getPrevious() : null;
+
+                if ($modelNotFoundException) {
+                    $json = [
+                        'message' => 'model_not_found',
+                        'model' => Str::snake(class_basename($modelNotFoundException->getModel())),
+                        'ids' => $modelNotFoundException->getIds(),
+                    ];
+
+                    return response()->json($json, 404);
+                }
+            }
+        });
     }
 }
diff --git a/app/Http/Controllers/api/v1/RoomMemberController.php b/app/Http/Controllers/api/v1/RoomMemberController.php
index 35d8aa78d..3a255cadf 100644
--- a/app/Http/Controllers/api/v1/RoomMemberController.php
+++ b/app/Http/Controllers/api/v1/RoomMemberController.php
@@ -122,14 +122,11 @@ public function bulkImport(Room $room, BulkImportRequest $request)
      *
      * @return Response
      */
-    public function update(Room $room, User $user, UpdateRoomMemberRequest $request)
+    public function update(Room $room, User $member, UpdateRoomMemberRequest $request)
     {
-        if (! $room->members->contains($user)) {
-            abort(410, __('app.errors.not_member_of_room'));
-        }
-        $room->members()->updateExistingPivot($user, ['role' => $request->role]);
+        $room->members()->updateExistingPivot($member, ['role' => $request->role]);
 
-        Log::info('Changed role for member {member} to {role} in room {room}', ['room' => $room->getLogLabel(), 'role' => RoomUserRole::from($request->role)->label(), 'member' => $user->getLogLabel()]);
+        Log::info('Changed role for member {member} to {role} in room {room}', ['room' => $room->getLogLabel(), 'role' => RoomUserRole::from($request->role)->label(), 'member' => $member->getLogLabel()]);
 
         return response()->noContent();
     }
@@ -155,14 +152,11 @@ public function bulkUpdate(Room $room, BulkUpdateRequest $request)
      *
      * @return Response
      */
-    public function destroy(Room $room, User $user)
+    public function destroy(Room $room, User $member)
     {
-        if (! $room->members->contains($user)) {
-            abort(410, __('app.errors.not_member_of_room'));
-        }
-        $room->members()->detach($user);
+        $room->members()->detach($member);
 
-        Log::info('Removed member {member} from room {room}', ['room' => $room->getLogLabel(), 'member' => $user->getLogLabel()]);
+        Log::info('Removed member {member} from room {room}', ['room' => $room->getLogLabel(), 'member' => $member->getLogLabel()]);
 
         return response()->noContent();
     }
diff --git a/app/Http/Controllers/api/v1/RoomPersonalizedLinkController.php b/app/Http/Controllers/api/v1/RoomPersonalizedLinkController.php
index e7158bb51..4b29b87a8 100644
--- a/app/Http/Controllers/api/v1/RoomPersonalizedLinkController.php
+++ b/app/Http/Controllers/api/v1/RoomPersonalizedLinkController.php
@@ -103,20 +103,16 @@ public function store(Room $room, RoomPersonalizedLinkRequest $request)
      *
      * @return RoomPersonalizedLinkResource
      */
-    public function update(Room $room, RoomPersonalizedLink $link, RoomPersonalizedLinkRequest $request)
+    public function update(Room $room, RoomPersonalizedLink $personalizedLink, RoomPersonalizedLinkRequest $request)
     {
-        if (! $link->room->is($room)) {
-            abort(404, __('app.errors.personalized_link_not_found'));
-        }
-
-        $link->firstname = $request->firstname;
-        $link->lastname = $request->lastname;
-        $link->role = $request->role;
-        $link->save();
+        $personalizedLink->firstname = $request->firstname;
+        $personalizedLink->lastname = $request->lastname;
+        $personalizedLink->role = $request->role;
+        $personalizedLink->save();
 
-        Log::info('Updated personalized room link for guest {name} with the role {role} for room {room}', ['room' => $room->getLogLabel(), 'role' => $link->role->label(), 'name' => $link->fullname]);
+        Log::info('Updated personalized room link for guest {name} with the role {role} for room {room}', ['room' => $room->getLogLabel(), 'role' => $personalizedLink->role->label(), 'name' => $personalizedLink->fullname]);
 
-        return new RoomPersonalizedLinkResource($link);
+        return new RoomPersonalizedLinkResource($personalizedLink);
     }
 
     /**
@@ -126,15 +122,11 @@ public function update(Room $room, RoomPersonalizedLink $link, RoomPersonalizedL
      *
      * @throws \Exception
      */
-    public function destroy(Room $room, RoomPersonalizedLink $link)
+    public function destroy(Room $room, RoomPersonalizedLink $personalizedLink)
     {
-        if (! $link->room->is($room)) {
-            abort(404, __('app.errors.personalized_link_not_found'));
-        }
-
-        $link->delete();
+        $personalizedLink->delete();
 
-        Log::info('Removed personalized room link for guest {name} with the role {role} for room {room}', ['room' => $room->getLogLabel(), 'role' => $link->role->label(), 'name' => $link->fullname]);
+        Log::info('Removed personalized room link for guest {name} with the role {role} for room {room}', ['room' => $room->getLogLabel(), 'role' => $personalizedLink->role->label(), 'name' => $personalizedLink->fullname]);
 
         return response()->noContent();
     }
diff --git a/lang/en/app.php b/lang/en/app.php
index 3782829de..fe001afa4 100644
--- a/lang/en/app.php
+++ b/lang/en/app.php
@@ -43,7 +43,7 @@
         'membership_disabled' => 'Membership failed! Membership for this room is currently not available.',
         'no_room_access' => 'You does not have the necessary permissions, to edit this room.',
         'no_server_available' => 'Currently there are no servers available.',
-        'not_member_of_room' => 'The person is not a member of this room (anymore).',
+        'not_member_of_room' => 'The user is not a member of this room.',
         'not_running' => 'Joining the room has failed as it is currently closed.',
         'personalized_link_not_found' => 'The personalized room link could not be found.',
         'record_agreement_missing' => 'Consent to the recording is required.',
@@ -66,6 +66,10 @@
     'flash' => [
         'client_error' => 'An unknown error occurred in the application!',
         'guests_only' => 'The request can only be made by guests!',
+        'model_not_found' => [
+            'title' => 'The :model was not found!',
+            'details' => 'Ids: :ids',
+        ],
         'server_error' => [
             'empty_message' => 'An error occurred on the server during request!',
             'error_code' => 'Error code: :statusCode',
@@ -97,10 +101,21 @@
         'fr' => 'French',
     ],
     'model' => [
+        'meeting' => 'Meeting',
+        'recording' => 'Recording',
+        'recording_format' => 'Recording format',
+        'role' => 'Role',
         'roles' => 'role',
+        'room' => 'Room',
+        'room_file' => 'Room file',
+        'room_personalized_link' => 'Room personalized link',
+        'room_type' => 'Room type',
         'room_types' => 'room type',
+        'server' => 'Server',
+        'server_pool' => 'Server pool',
         'server_pools' => 'server pool',
         'servers' => 'server',
+        'user' => 'User',
         'users' => 'user',
     ],
     'model_name' => 'Name',
diff --git a/resources/js/components/RoomCard.vue b/resources/js/components/RoomCard.vue
index af48193fe..93617d18d 100644
--- a/resources/js/components/RoomCard.vue
+++ b/resources/js/components/RoomCard.vue
@@ -35,6 +35,7 @@
                 <RoomFavoriteButton
                   :room="props.room"
                   class="room-card-button h-8 w-8 p-0 text-sm"
+                  :redirect-on-room-model-not-found="false"
                   @favorites-changed="$emit('favoritesChanged')"
                 />
               </div>
@@ -72,6 +73,7 @@
         <div class="room-card-buttons shrink-0">
           <RoomFavoriteButton
             :room="props.room"
+            :redirect-on-room-model-not-found="false"
             @favorites-changed="$emit('favoritesChanged')"
           />
         </div>
diff --git a/resources/js/components/RoomFavoriteButton.vue b/resources/js/components/RoomFavoriteButton.vue
index 0e64e9ef8..fd0439d7b 100644
--- a/resources/js/components/RoomFavoriteButton.vue
+++ b/resources/js/components/RoomFavoriteButton.vue
@@ -33,6 +33,10 @@ const props = defineProps({
     type: Boolean,
     default: true,
   },
+  redirectOnRoomModelNotFound: {
+    type: Boolean,
+    default: true,
+  },
 });
 
 const isLoading = ref(false);
@@ -57,6 +61,7 @@ function toggleFavorite() {
     .catch((error) => {
       api.error(error, {
         redirectOnUnauthenticated: props.redirectOnUnauthenticated,
+        redirectOnRoomModelNotFound: props.redirectOnRoomModelNotFound,
       });
     })
     .finally(() => {
diff --git a/resources/js/components/RoomTabFilesDeleteButton.vue b/resources/js/components/RoomTabFilesDeleteButton.vue
index 184663335..e383b1471 100644
--- a/resources/js/components/RoomTabFilesDeleteButton.vue
+++ b/resources/js/components/RoomTabFilesDeleteButton.vue
@@ -53,6 +53,7 @@ import { useApi } from "../composables/useApi.js";
 import { ref } from "vue";
 import { useToast } from "../composables/useToast.js";
 import { useI18n } from "vue-i18n";
+import { ROOM_FILE } from "../constants/modelNames.js";
 
 const props = defineProps({
   roomId: {
@@ -101,7 +102,10 @@ function deleteFile() {
       // deleting failed
       if (error.response) {
         // file not found
-        if (error.response.status === env.HTTP_NOT_FOUND) {
+        if (
+          error.response.status === env.HTTP_NOT_FOUND &&
+          error.response.data?.model === ROOM_FILE
+        ) {
           toast.error(t("rooms.flash.file_gone"));
           emit("notFound");
           modalVisible.value = false;
diff --git a/resources/js/components/RoomTabFilesEditButton.vue b/resources/js/components/RoomTabFilesEditButton.vue
index 25362cdb5..f602dbc31 100644
--- a/resources/js/components/RoomTabFilesEditButton.vue
+++ b/resources/js/components/RoomTabFilesEditButton.vue
@@ -100,6 +100,7 @@ import { ref, watch } from "vue";
 import { useFormErrors } from "../composables/useFormErrors.js";
 import { useToast } from "../composables/useToast.js";
 import { useI18n } from "vue-i18n";
+import { ROOM_FILE } from "../constants/modelNames.js";
 
 const props = defineProps({
   roomId: {
@@ -195,7 +196,10 @@ function save() {
       // editing failed
       if (error.response) {
         // file not found
-        if (error.response.status === env.HTTP_NOT_FOUND) {
+        if (
+          error.response.status === env.HTTP_NOT_FOUND &&
+          error.response.data?.model === ROOM_FILE
+        ) {
           toast.error(t("rooms.flash.file_gone"));
           emit("notFound");
           modalVisible.value = false;
diff --git a/resources/js/components/RoomTabMembersDeleteButton.vue b/resources/js/components/RoomTabMembersDeleteButton.vue
index cf30ba516..06c481399 100644
--- a/resources/js/components/RoomTabMembersDeleteButton.vue
+++ b/resources/js/components/RoomTabMembersDeleteButton.vue
@@ -56,6 +56,9 @@
 import env from "../env";
 import { useApi } from "../composables/useApi.js";
 import { ref } from "vue";
+import { USER } from "../constants/modelNames.js";
+import { useToast } from "../composables/useToast.js";
+import { useI18n } from "vue-i18n";
 
 const props = defineProps({
   roomId: {
@@ -83,6 +86,8 @@ const props = defineProps({
 const emit = defineEmits(["deleted", "gone"]);
 
 const api = useApi();
+const toast = useToast();
+const { t } = useI18n();
 
 const modalVisible = ref(false);
 const isLoadingAction = ref(false);
@@ -106,9 +111,14 @@ function deleteMember() {
       // editing failed
       if (error.response) {
         // user not found
-        if (error.response.status === env.HTTP_GONE) {
+        if (
+          error.response.status === env.HTTP_NOT_FOUND &&
+          error.response.data?.model === USER
+        ) {
+          toast.error(t("app.errors.not_member_of_room"));
           emit("gone");
           modalVisible.value = false;
+          return;
         }
       }
       api.error(error, { redirectOnUnauthenticated: false });
diff --git a/resources/js/components/RoomTabMembersEditButton.vue b/resources/js/components/RoomTabMembersEditButton.vue
index 8a02bed35..518837fca 100644
--- a/resources/js/components/RoomTabMembersEditButton.vue
+++ b/resources/js/components/RoomTabMembersEditButton.vue
@@ -99,6 +99,9 @@ import env from "../env";
 import { useApi } from "../composables/useApi.js";
 import { useFormErrors } from "../composables/useFormErrors.js";
 import { ref } from "vue";
+import { USER } from "../constants/modelNames.js";
+import { useToast } from "../composables/useToast.js";
+import { useI18n } from "vue-i18n";
 
 const props = defineProps({
   roomId: {
@@ -131,6 +134,8 @@ const emit = defineEmits(["edited", "gone"]);
 
 const api = useApi();
 const formErrors = useFormErrors();
+const toast = useToast();
+const { t } = useI18n();
 
 const modalVisible = ref(false);
 const newRole = ref(null);
@@ -168,9 +173,14 @@ function save() {
       // editing failed
       if (error.response) {
         // user not found
-        if (error.response.status === env.HTTP_GONE) {
+        if (
+          error.response.status === env.HTTP_NOT_FOUND &&
+          error.response.data?.model === USER
+        ) {
+          toast.error(t("app.errors.not_member_of_room"));
           emit("gone");
           modalVisible.value = false;
+          return;
         }
         // failed due to form validation errors
         if (error.response.status === env.HTTP_UNPROCESSABLE_ENTITY) {
diff --git a/resources/js/components/RoomTabPersonalizedLinksDeleteButton.vue b/resources/js/components/RoomTabPersonalizedLinksDeleteButton.vue
index cd2e998ad..aa7f1ca78 100644
--- a/resources/js/components/RoomTabPersonalizedLinksDeleteButton.vue
+++ b/resources/js/components/RoomTabPersonalizedLinksDeleteButton.vue
@@ -59,6 +59,7 @@ import { useApi } from "../composables/useApi.js";
 import { ref } from "vue";
 import { useToast } from "../composables/useToast.js";
 import { useI18n } from "vue-i18n";
+import { ROOM_PERSONALIZED_LINK } from "../constants/modelNames.js";
 
 const props = defineProps({
   roomId: {
@@ -120,7 +121,10 @@ function deleteLink() {
       // deleting failed
       if (error.response) {
         // personalized link not found
-        if (error.response.status === env.HTTP_NOT_FOUND) {
+        if (
+          error.response.status === env.HTTP_NOT_FOUND &&
+          error.response.data?.model === ROOM_PERSONALIZED_LINK
+        ) {
           toast.error(t("rooms.flash.personalized_link_gone"));
           modalVisible.value = false;
           emit("notFound");
diff --git a/resources/js/components/RoomTabPersonalizedLinksEditButton.vue b/resources/js/components/RoomTabPersonalizedLinksEditButton.vue
index 7dde482ad..937988c60 100644
--- a/resources/js/components/RoomTabPersonalizedLinksEditButton.vue
+++ b/resources/js/components/RoomTabPersonalizedLinksEditButton.vue
@@ -110,6 +110,7 @@ import { ref } from "vue";
 import env from "../env.js";
 import { useToast } from "../composables/useToast.js";
 import { useI18n } from "vue-i18n";
+import { ROOM_PERSONALIZED_LINK } from "../constants/modelNames.js";
 
 const props = defineProps({
   roomId: {
@@ -189,7 +190,10 @@ function save() {
       // editing failed
       if (error.response) {
         // token not found
-        if (error.response.status === env.HTTP_NOT_FOUND) {
+        if (
+          error.response.status === env.HTTP_NOT_FOUND &&
+          error.response.data?.model === ROOM_PERSONALIZED_LINK
+        ) {
           toast.error(t("rooms.flash.personalized_link_gone"));
           modalVisible.value = false;
           emit("notFound");
diff --git a/resources/js/components/RoomTabRecordingsDeleteButton.vue b/resources/js/components/RoomTabRecordingsDeleteButton.vue
index 326f8f533..553d4a80f 100644
--- a/resources/js/components/RoomTabRecordingsDeleteButton.vue
+++ b/resources/js/components/RoomTabRecordingsDeleteButton.vue
@@ -53,6 +53,7 @@ import { useApi } from "../composables/useApi.js";
 import { ref } from "vue";
 import { useToast } from "../composables/useToast.js";
 import { useI18n } from "vue-i18n";
+import { RECORDING } from "../constants/modelNames.js";
 
 const props = defineProps({
   recordingId: {
@@ -97,7 +98,10 @@ function deleteRecording() {
       // editing failed
       if (error.response) {
         // recording not found
-        if (error.response.status === env.HTTP_NOT_FOUND) {
+        if (
+          error.response.status === env.HTTP_NOT_FOUND &&
+          error.response.data?.model === RECORDING
+        ) {
           toast.error(t("rooms.flash.recording_gone"));
           emit("notFound");
           return;
diff --git a/resources/js/components/RoomTabRecordingsEditButton.vue b/resources/js/components/RoomTabRecordingsEditButton.vue
index f07787a4d..654a0d005 100644
--- a/resources/js/components/RoomTabRecordingsEditButton.vue
+++ b/resources/js/components/RoomTabRecordingsEditButton.vue
@@ -130,6 +130,7 @@ import * as _ from "lodash-es";
 import { useSettingsStore } from "../stores/settings.js";
 import { useToast } from "../composables/useToast.js";
 import { useI18n } from "vue-i18n";
+import { RECORDING } from "../constants/modelNames.js";
 
 const props = defineProps({
   recordingId: {
@@ -236,7 +237,10 @@ function save() {
       // editing failed
       if (error.response) {
         // recording not found
-        if (error.response.status === env.HTTP_NOT_FOUND) {
+        if (
+          error.response.status === env.HTTP_NOT_FOUND &&
+          error.response.data?.model === RECORDING
+        ) {
           toast.error(t("rooms.flash.recording_gone"));
           modalVisible.value = false;
           emit("notFound");
diff --git a/resources/js/components/SettingsRolesDeleteButton.vue b/resources/js/components/SettingsRolesDeleteButton.vue
index 61f2a9e1d..76a6afa7a 100644
--- a/resources/js/components/SettingsRolesDeleteButton.vue
+++ b/resources/js/components/SettingsRolesDeleteButton.vue
@@ -46,6 +46,7 @@
 <script setup>
 import { ref } from "vue";
 import { useApi } from "../composables/useApi.js";
+import env from "../env.js";
 
 const api = useApi();
 
@@ -60,7 +61,7 @@ const props = defineProps({
   },
 });
 
-const emit = defineEmits(["deleted"]);
+const emit = defineEmits(["deleted", "notFound"]);
 
 const modalVisible = ref(false);
 const isBusy = ref(false);
@@ -88,6 +89,10 @@ function deleteRole() {
       emit("deleted");
     })
     .catch((error) => {
+      if (error.response && error.response.status === env.HTTP_NOT_FOUND) {
+        modalVisible.value = false;
+        emit("notFound");
+      }
       api.error(error);
     })
     .finally(() => {
diff --git a/resources/js/components/SettingsServerPoolsDeleteButton.vue b/resources/js/components/SettingsServerPoolsDeleteButton.vue
index 14c460bd6..08a531764 100644
--- a/resources/js/components/SettingsServerPoolsDeleteButton.vue
+++ b/resources/js/components/SettingsServerPoolsDeleteButton.vue
@@ -84,7 +84,7 @@ const props = defineProps({
   },
 });
 
-const emit = defineEmits(["deleted"]);
+const emit = defineEmits(["deleted", "notFound"]);
 const modalVisible = ref(false);
 const isBusy = ref(false);
 const deleteFailedRoomTypes = ref(null);
@@ -115,9 +115,15 @@ function deleteServerPool() {
     .catch((error) => {
       if (error.response && error.response.status === env.HTTP_STALE_MODEL) {
         deleteFailedRoomTypes.value = error.response.data.room_types;
-      } else {
-        api.error(error);
+        return;
+      } else if (
+        error.response &&
+        error.response.status === env.HTTP_NOT_FOUND
+      ) {
+        modalVisible.value = false;
+        emit("notFound");
       }
+      api.error(error);
     })
     .finally(() => {
       isBusy.value = false;
diff --git a/resources/js/components/SettingsServersDeleteButton.vue b/resources/js/components/SettingsServersDeleteButton.vue
index c1e69b5ab..7fc41200e 100644
--- a/resources/js/components/SettingsServersDeleteButton.vue
+++ b/resources/js/components/SettingsServersDeleteButton.vue
@@ -44,6 +44,7 @@
 <script setup>
 import { useApi } from "../composables/useApi.js";
 import { ref } from "vue";
+import env from "../env.js";
 
 const api = useApi();
 
@@ -58,7 +59,7 @@ const props = defineProps({
   },
 });
 
-const emit = defineEmits(["deleted"]);
+const emit = defineEmits(["deleted", "notFound"]);
 const modalVisible = ref(false);
 const isBusy = ref(false);
 
@@ -85,6 +86,10 @@ function deleteServer() {
       emit("deleted");
     })
     .catch((error) => {
+      if (error.response && error.response.status === env.HTTP_NOT_FOUND) {
+        modalVisible.value = false;
+        emit("notFound");
+      }
       api.error(error);
     })
     .finally(() => {
diff --git a/resources/js/components/SettingsUsersDeleteButton.vue b/resources/js/components/SettingsUsersDeleteButton.vue
index 9195e23ed..e9f05a0ec 100644
--- a/resources/js/components/SettingsUsersDeleteButton.vue
+++ b/resources/js/components/SettingsUsersDeleteButton.vue
@@ -60,6 +60,7 @@
 <script setup>
 import { ref } from "vue";
 import { useApi } from "../composables/useApi.js";
+import env from "../env.js";
 
 const api = useApi();
 
@@ -78,7 +79,7 @@ const props = defineProps({
   },
 });
 
-const emit = defineEmits(["deleted"]);
+const emit = defineEmits(["deleted", "notFound"]);
 const modalVisible = ref(false);
 const isBusy = ref(false);
 
@@ -105,6 +106,10 @@ function deleteUser() {
       emit("deleted");
     })
     .catch((error) => {
+      if (error.response && error.response.status === env.HTTP_NOT_FOUND) {
+        modalVisible.value = false;
+        emit("notFound");
+      }
       api.error(error);
     })
     .finally(() => {
diff --git a/resources/js/components/SettingsUsersResetPasswordButton.vue b/resources/js/components/SettingsUsersResetPasswordButton.vue
index d46442290..11fdb3946 100644
--- a/resources/js/components/SettingsUsersResetPasswordButton.vue
+++ b/resources/js/components/SettingsUsersResetPasswordButton.vue
@@ -64,6 +64,7 @@ import { ref } from "vue";
 import { useApi } from "../composables/useApi.js";
 import { useToast } from "../composables/useToast.js";
 import { useI18n } from "vue-i18n";
+import env from "../env.js";
 
 const api = useApi();
 const toast = useToast();
@@ -88,6 +89,7 @@ const props = defineProps({
   },
 });
 
+const emit = defineEmits(["notFound"]);
 const modalVisible = ref(false);
 const isBusy = ref(false);
 
@@ -114,6 +116,10 @@ function resetPassword() {
       );
     })
     .catch((error) => {
+      if (error.response && error.response.status === env.HTTP_NOT_FOUND) {
+        modalVisible.value = false;
+        emit("notFound");
+      }
       api.error(error);
     })
     .finally(() => {
diff --git a/resources/js/constants/modelNames.js b/resources/js/constants/modelNames.js
new file mode 100644
index 000000000..60d9f8a1e
--- /dev/null
+++ b/resources/js/constants/modelNames.js
@@ -0,0 +1,5 @@
+export const ROOM = "room";
+export const ROOM_FILE = "room_file";
+export const ROOM_PERSONALIZED_LINK = "room_personalized_link";
+export const RECORDING = "recording";
+export const USER = "user";
diff --git a/resources/js/services/Api.js b/resources/js/services/Api.js
index d70623a9e..d783aeccc 100644
--- a/resources/js/services/Api.js
+++ b/resources/js/services/Api.js
@@ -6,6 +6,7 @@ import { useAuthStore } from "../stores/auth";
 import { useRouter } from "vue-router";
 import { EVENT_FORBIDDEN, EVENT_UNAUTHORIZED } from "../constants/events.js";
 import EventBus from "./EventBus.js";
+import { ROOM } from "../constants/modelNames.js";
 
 axios.defaults.withCredentials = true;
 axios.defaults.headers.common["X-Requested-With"] = "XMLHttpRequest";
@@ -61,6 +62,13 @@ export class Api {
     ) {
       // 403 => unauthorized, show error messages as flash!
       this.handleForbidden(error, options);
+    } else if (statusCode === env.HTTP_NOT_FOUND) {
+      // 404 => not found, show error messages as flash!
+      if (message === "model_not_found") {
+        this.handleModelNotFound(error, options);
+      } else {
+        this.handleOtherServerError(error, options);
+      }
     } else if (statusCode === env.HTTP_GUESTS_ONLY) {
       // 420 => only for guests, redirect to home route
       this.handleGuestsOnly(error, options);
@@ -112,6 +120,29 @@ export class Api {
     this.toast.error(this.t("app.flash.unauthorized"));
   }
 
+  handleModelNotFound(error, options) {
+    const data = error.response?.data;
+    const model = data?.model;
+    const ids = data?.ids;
+
+    if (model === ROOM && options.redirectOnRoomModelNotFound !== false) {
+      // Redirect to room index page if user is authenticated, otherwise show 404 page, because
+      // unauthenticated user is not able to visit the room index page
+      if (this.auth.isAuthenticated) {
+        this.router.push({ name: "rooms.index" });
+      } else {
+        this.router.push({ name: "404" });
+      }
+    }
+
+    this.toast.error(
+      this.t("app.flash.model_not_found.title", {
+        model: this.t("app.model." + model),
+      }),
+      this.t("app.flash.model_not_found.details", { ids: `${ids.join(", ")}` }),
+    );
+  }
+
   handleGuestsOnly() {
     this.toast.info(this.t("app.flash.guests_only"));
     this.router.replace({ name: "home" });
diff --git a/resources/js/views/AdminRolesIndex.vue b/resources/js/views/AdminRolesIndex.vue
index dccb35820..995be719a 100644
--- a/resources/js/views/AdminRolesIndex.vue
+++ b/resources/js/views/AdminRolesIndex.vue
@@ -149,6 +149,7 @@
               :id="slotProps.data.id"
               :name="slotProps.data.name"
               @deleted="loadData()"
+              @not-found="loadData()"
             />
           </div>
         </template>
diff --git a/resources/js/views/AdminRolesView.vue b/resources/js/views/AdminRolesView.vue
index 0ff015a9e..2c6b1375c 100644
--- a/resources/js/views/AdminRolesView.vue
+++ b/resources/js/views/AdminRolesView.vue
@@ -30,6 +30,7 @@
           :id="model.id"
           :name="name"
           @deleted="$router.push({ name: 'admin.roles' })"
+          @not-found="$router.push({ name: 'admin.roles' })"
         />
       </div>
     </div>
diff --git a/resources/js/views/AdminRoomTypesView.vue b/resources/js/views/AdminRoomTypesView.vue
index f9ee07da4..83a0a5ca5 100644
--- a/resources/js/views/AdminRoomTypesView.vue
+++ b/resources/js/views/AdminRoomTypesView.vue
@@ -27,6 +27,7 @@
           :id="model.id"
           :name="name"
           @deleted="$router.push({ name: 'admin.room_types' })"
+          @not-found="$router.push({ name: 'admin.room_types' })"
         />
       </div>
     </div>
diff --git a/resources/js/views/AdminServerPoolsIndex.vue b/resources/js/views/AdminServerPoolsIndex.vue
index 7d42bd96b..463aa5788 100644
--- a/resources/js/views/AdminServerPoolsIndex.vue
+++ b/resources/js/views/AdminServerPoolsIndex.vue
@@ -145,6 +145,7 @@
               :id="slotProps.data.id"
               :name="slotProps.data.name"
               @deleted="loadData()"
+              @not-found="loadData()"
             >
             </SettingsServerPoolsDeleteButton>
           </div>
diff --git a/resources/js/views/AdminServerPoolsView.vue b/resources/js/views/AdminServerPoolsView.vue
index 9fae0bd3c..f4b9dfeda 100644
--- a/resources/js/views/AdminServerPoolsView.vue
+++ b/resources/js/views/AdminServerPoolsView.vue
@@ -27,6 +27,7 @@
           :id="model.id"
           :name="name"
           @deleted="$router.push({ name: 'admin.server_pools' })"
+          @not-found="$router.push({ name: 'admin.server_pools' })"
         >
         </SettingsServerPoolsDeleteButton>
       </div>
diff --git a/resources/js/views/AdminServersIndex.vue b/resources/js/views/AdminServersIndex.vue
index 1854d059c..abcc30e37 100644
--- a/resources/js/views/AdminServersIndex.vue
+++ b/resources/js/views/AdminServersIndex.vue
@@ -268,6 +268,7 @@
               :id="slotProps.data.id"
               :name="slotProps.data.name"
               @deleted="loadData(null, false)"
+              @not-found="loadData(null, false)"
             ></SettingsServersDeleteButton>
           </div>
         </template>
diff --git a/resources/js/views/AdminServersView.vue b/resources/js/views/AdminServersView.vue
index 413fcda17..1a57f8abb 100644
--- a/resources/js/views/AdminServersView.vue
+++ b/resources/js/views/AdminServersView.vue
@@ -27,6 +27,7 @@
           :id="model.id"
           :name="name"
           @deleted="$router.push({ name: 'admin.servers' })"
+          @not-found="$router.push({ name: 'admin.servers' })"
         ></SettingsServersDeleteButton>
       </div>
     </div>
@@ -475,6 +476,9 @@ function panic() {
       }
     })
     .catch((error) => {
+      if (error.response && error.response.status === env.HTTP_NOT_FOUND) {
+        router.push({ name: "admin.servers" });
+      }
       api.error(error);
     })
     .finally(() => {
@@ -516,6 +520,7 @@ function testConnection() {
     .catch((error) => {
       health.value = null;
       offlineReason.value = null;
+
       api.error(error);
     })
     .finally(() => {
diff --git a/resources/js/views/AdminUsersIndex.vue b/resources/js/views/AdminUsersIndex.vue
index 71c0ead92..f352153f5 100644
--- a/resources/js/views/AdminUsersIndex.vue
+++ b/resources/js/views/AdminUsersIndex.vue
@@ -300,6 +300,7 @@
               :firstname="slotProps.data.firstname"
               :lastname="slotProps.data.lastname"
               :email="slotProps.data.email"
+              @not-found="loadData()"
             />
             <SettingsUsersDeleteButton
               v-if="userPermissions.can('delete', slotProps.data)"
@@ -307,6 +308,7 @@
               :firstname="slotProps.data.firstname"
               :lastname="slotProps.data.lastname"
               @deleted="loadData()"
+              @not-found="loadData()"
             />
           </div>
         </template>
diff --git a/resources/js/views/AdminUsersView.vue b/resources/js/views/AdminUsersView.vue
index 6fd17f016..9b620728f 100644
--- a/resources/js/views/AdminUsersView.vue
+++ b/resources/js/views/AdminUsersView.vue
@@ -30,6 +30,7 @@
           :firstname="user.firstname"
           :lastname="user.lastname"
           :email="user.email"
+          @not-found="$router.push({ name: 'admin.users' })"
         />
         <SettingsUsersDeleteButton
           v-if="userPermissions.can('delete', user)"
@@ -37,6 +38,7 @@
           :firstname="user.firstname"
           :lastname="user.lastname"
           @deleted="$router.push({ name: 'admin.users' })"
+          @not-found="$router.push({ name: 'admin.users' })"
         />
       </div>
     </div>
diff --git a/resources/js/views/RoomsView.vue b/resources/js/views/RoomsView.vue
index 9453a6d35..961dd0553 100644
--- a/resources/js/views/RoomsView.vue
+++ b/resources/js/views/RoomsView.vue
@@ -463,10 +463,13 @@ function load() {
     })
     .catch((error) => {
       if (error.response) {
-        // Room not found
+        // Room not found (Always redirect to 404 view or room index page)
         if (error.response.status === env.HTTP_NOT_FOUND) {
-          router.push({ name: "404" });
-          return;
+          if (authStore.isAuthenticated) {
+            router.push({ name: "rooms.index" });
+          } else {
+            router.push({ name: "404" });
+          }
         }
 
         // Room auth token is invalid
@@ -487,7 +490,10 @@ function load() {
         }
       }
 
-      api.error(error, { redirectOnUnauthenticated: false });
+      api.error(error, {
+        redirectOnUnauthenticated: false,
+        redirectOnRoomModelNotFound: false,
+      });
     })
     .finally(() => {
       // Disable loading indicator
@@ -549,10 +555,13 @@ function reload(checkForRequireCodeError = true) {
     })
     .catch((error) => {
       if (error.response) {
-        // Room not found
+        // Room not found (Always redirect to 404 view or room index page)
         if (error.response.status === env.HTTP_NOT_FOUND) {
-          router.push({ name: "404" });
-          return;
+          if (authStore.isAuthenticated) {
+            router.push({ name: "rooms.index" });
+          } else {
+            router.push({ name: "404" });
+          }
         }
 
         // Room auth token is invalid
@@ -571,7 +580,10 @@ function reload(checkForRequireCodeError = true) {
           return handleGuestsNotAllowed();
         }
       }
-      api.error(error, { redirectOnUnauthenticated: false });
+      api.error(error, {
+        redirectOnUnauthenticated: false,
+        redirectOnRoomModelNotFound: false,
+      });
     })
     .finally(() => {
       // Disable loading indicator
@@ -708,7 +720,9 @@ function authenticate(type, codeOrToken) {
             return;
           }
         }
-        api.error(error, { redirectOnUnauthenticated: false });
+        api.error(error, {
+          redirectOnUnauthenticated: false,
+        });
       })
       .finally(() => {
         authLoading.value = false;
diff --git a/routes/api.php b/routes/api.php
index 897f389b5..260df03cf 100644
--- a/routes/api.php
+++ b/routes/api.php
@@ -75,7 +75,7 @@
         Route::get('rooms', [RoomController::class, 'index'])->name('rooms.index');
         Route::post('rooms', [RoomController::class, 'store'])->name('rooms.store');
 
-        Route::middleware('throttle:room-enumeration')->group(function () {
+        Route::middleware('throttle:room-enumeration')->scopeBindings()->group(function () {
             Route::post('rooms/{room}/favorites', [RoomController::class, 'addToFavorites'])->name('rooms.favorites.add');
             Route::delete('rooms/{room}/favorites', [RoomController::class, 'deleteFromFavorites'])->name('rooms.favorites.delete');
             Route::put('rooms/{room}', [RoomController::class, 'update'])->name('rooms.update');
@@ -91,30 +91,33 @@
             Route::post('rooms/{room}/membership', [RoomMemberController::class, 'join'])->name('rooms.membership.join');
             Route::delete('rooms/{room}/membership', [RoomMemberController::class, 'leave'])->name('rooms.membership.leave');
 
-            // Membership users for mass update & delete
-            Route::post('rooms/{room}/member/bulk', [RoomMemberController::class, 'bulkImport'])->name('rooms.member.bulkImport')->middleware('can:manageMembers,room');
-            Route::put('rooms/{room}/member/bulk', [RoomMemberController::class, 'bulkUpdate'])->name('rooms.member.bulkUpdate')->middleware('can:manageMembers,room');
-            Route::delete('rooms/{room}/member/bulk', [RoomMemberController::class, 'bulkDestroy'])->name('rooms.member.bulkDestroy')->middleware('can:manageMembers,room');
-
             // Membership operations by room owner
             Route::get('rooms/{room}/member', [RoomMemberController::class, 'index'])->name('rooms.member.get')->middleware('can:viewMembers,room');
-            Route::post('rooms/{room}/member', [RoomMemberController::class, 'store'])->name('rooms.member.add')->middleware('can:manageMembers,room');
-            Route::put('rooms/{room}/member/{user}', [RoomMemberController::class, 'update'])->name('rooms.member.update')->middleware('can:manageMembers,room');
-            Route::delete('rooms/{room}/member/{user}', [RoomMemberController::class, 'destroy'])->name('rooms.member.destroy')->middleware('can:manageMembers,room');
+
+            Route::middleware('can:manageMembers,room')->group(function () {
+                // Membership users for mass update & delete
+                Route::post('rooms/{room}/member/bulk', [RoomMemberController::class, 'bulkImport'])->name('rooms.member.bulkImport');
+                Route::put('rooms/{room}/member/bulk', [RoomMemberController::class, 'bulkUpdate'])->name('rooms.member.bulkUpdate');
+                Route::delete('rooms/{room}/member/bulk', [RoomMemberController::class, 'bulkDestroy'])->name('rooms.member.bulkDestroy');
+
+                Route::post('rooms/{room}/member', [RoomMemberController::class, 'store'])->name('rooms.member.add');
+                Route::put('rooms/{room}/member/{member}', [RoomMemberController::class, 'update'])->name('rooms.member.update');
+                Route::delete('rooms/{room}/member/{member}', [RoomMemberController::class, 'destroy'])->name('rooms.member.destroy');
+            });
 
             // Recording operations
-            Route::middleware('can:manageRecordings,room')->scopeBindings()->group(function () {
+            Route::middleware('can:manageRecordings,room')->group(function () {
                 Route::put('rooms/{room}/recordings/{recording}', [RecordingController::class, 'update'])->name('rooms.recordings.update');
                 Route::delete('rooms/{room}/recordings/{recording}', [RecordingController::class, 'destroy'])->name('rooms.recordings.destroy');
             });
 
             // Streaming operations
-            Route::middleware('can:viewStreaming,room')->scopeBindings()->group(function () {
+            Route::middleware('can:viewStreaming,room')->group(function () {
                 Route::get('rooms/{room}/streaming/config', [RoomStreamingController::class, 'getConfig'])->name('rooms.streaming.config.get');
                 Route::get('rooms/{room}/streaming/status', [RoomStreamingController::class, 'status'])->name('rooms.streaming.status');
             });
 
-            Route::middleware('can:manageStreaming,room')->scopeBindings()->group(function () {
+            Route::middleware('can:manageStreaming,room')->group(function () {
                 Route::put('rooms/{room}/streaming/config', [RoomStreamingController::class, 'updateConfig'])->name('rooms.streaming.config.update');
                 Route::post('rooms/{room}/streaming/start', [RoomStreamingController::class, 'start'])->name('rooms.streaming.start');
                 Route::post('rooms/{room}/streaming/stop', [RoomStreamingController::class, 'stop'])->name('rooms.streaming.stop');
@@ -124,12 +127,15 @@
 
             // Personalized room links
             Route::get('rooms/{room}/personalizedLinks', [RoomPersonalizedLinkController::class, 'index'])->name('rooms.personalizedLinks.get')->middleware('can:viewPersonalizedLinks,room');
-            Route::post('rooms/{room}/personalizedLinks', [RoomPersonalizedLinkController::class, 'store'])->name('rooms.personalizedLinks.add')->middleware('can:managePersonalizedLinks,room');
-            Route::put('rooms/{room}/personalizedLinks/{link}', [RoomPersonalizedLinkController::class, 'update'])->name('rooms.personalizedLinks.update')->middleware('can:managePersonalizedLinks,room');
-            Route::delete('rooms/{room}/personalizedLinks/{link}', [RoomPersonalizedLinkController::class, 'destroy'])->name('rooms.personalizedLinks.destroy')->middleware('can:managePersonalizedLinks,room');
+
+            Route::middleware('can:managePersonalizedLinks,room')->group(function () {
+                Route::post('rooms/{room}/personalizedLinks', [RoomPersonalizedLinkController::class, 'store'])->name('rooms.personalizedLinks.add');
+                Route::put('rooms/{room}/personalizedLinks/{personalizedLink}', [RoomPersonalizedLinkController::class, 'update'])->name('rooms.personalizedLinks.update');
+                Route::delete('rooms/{room}/personalizedLinks/{personalizedLink}', [RoomPersonalizedLinkController::class, 'destroy'])->name('rooms.personalizedLinks.destroy');
+            });
 
             // File operations
-            Route::middleware('can:manageFiles,room')->scopeBindings()->group(function () {
+            Route::middleware('can:manageFiles,room')->group(function () {
                 Route::post('rooms/{room}/files', [RoomFileController::class, 'store'])->name('rooms.files.add');
                 Route::put('rooms/{room}/files/{file}', [RoomFileController::class, 'update'])->name('rooms.files.update');
                 Route::delete('rooms/{room}/files/{file}', [RoomFileController::class, 'destroy'])->name('rooms.files.destroy');
diff --git a/tests/Backend/Feature/api/v1/RecordingTest.php b/tests/Backend/Feature/api/v1/RecordingTest.php
index 1e9992063..9e647e051 100644
--- a/tests/Backend/Feature/api/v1/RecordingTest.php
+++ b/tests/Backend/Feature/api/v1/RecordingTest.php
@@ -1129,6 +1129,28 @@ public function test_update()
         $this->assertTrue($podcast->disabled);
         $this->assertFalse($presentation->disabled);
         $this->assertTrue($notes->disabled);
+
+        // Test deleted recording
+        $recording->delete();
+
+        $this->putJson(route('api.v1.rooms.recordings.update', ['room' => $room->id, 'recording' => $recording->id]), $payload)
+            ->assertNotFound()
+            ->assertJson([
+                'message' => 'model_not_found',
+                'model' => 'recording',
+                'ids' => [$recording->id],
+            ]);
+
+        // Test deleted room
+        $room->delete();
+
+        $this->putJson(route('api.v1.rooms.recordings.update', ['room' => $room->id, 'recording' => $recording->id]), $payload)
+            ->assertNotFound()
+            ->assertJson([
+                'message' => 'model_not_found',
+                'model' => 'room',
+                'ids' => [$room->id],
+            ]);
     }
 
     public function test_update_permissions()
@@ -1226,7 +1248,12 @@ public function test_update_invalid_data()
         $otherRoom = Room::factory()->create();
         $this->actingAs($otherRoom->owner)
             ->putJson(route('api.v1.rooms.recordings.update', ['room' => $otherRoom->id, 'recording' => $recording->id]), $payload)
-            ->assertNotFound();
+            ->assertNotFound()
+            ->assertJson([
+                'message' => 'model_not_found',
+                'model' => 'recording',
+                'ids' => [$recording->id],
+            ]);
 
     }
 
@@ -1258,6 +1285,16 @@ public function test_delete()
 
         // Check storage
         $this->assertDirectoryDoesNotExist(Storage::disk('recordings')->path($recording->id));
+
+        // Test delete again
+        $this->actingAs($room->owner)
+            ->deleteJson(route('api.v1.rooms.recordings.destroy', ['room' => $room->id, 'recording' => $recording->id]))
+            ->assertNotFound()
+            ->assertJson([
+                'message' => 'model_not_found',
+                'model' => 'recording',
+                'ids' => [$recording->id],
+            ]);
     }
 
     public function test_delete_on_room_delete()
@@ -1355,7 +1392,12 @@ public function test_delete_invalid_data()
         $otherRoom = Room::factory()->create();
         $this->actingAs($otherRoom->owner)
             ->deleteJson(route('api.v1.rooms.recordings.destroy', ['room' => $otherRoom->id, 'recording' => $recording->id]))
-            ->assertNotFound();
+            ->assertNotFound()
+            ->assertJson([
+                'message' => 'model_not_found',
+                'model' => 'recording',
+                'ids' => [$recording->id],
+            ]);
     }
 
     public function test_access_recording_resource()
diff --git a/tests/Backend/Feature/api/v1/RoleTest.php b/tests/Backend/Feature/api/v1/RoleTest.php
index b7f02c589..2fe3c47e0 100644
--- a/tests/Backend/Feature/api/v1/RoleTest.php
+++ b/tests/Backend/Feature/api/v1/RoleTest.php
@@ -244,6 +244,17 @@ public function test_update()
         $this->putJson(route('api.v1.roles.update', ['role' => $role]), $changes)
             ->assertUnprocessable()
             ->assertJsonValidationErrors(['permissions', 'name', 'room_limit']);
+
+        // Test deleted
+        $role->delete();
+
+        $this->putJson(route('api.v1.roles.update', ['role' => $role]), $changes)
+            ->assertNotFound()
+            ->assertJson([
+                'message' => 'model_not_found',
+                'model' => 'role',
+                'ids' => [$role->id],
+            ]);
     }
 
     public function test_update_permission_lost()
@@ -329,7 +340,13 @@ public function test_show()
         $roleB->permissions()->attach($permission->id);
 
         $this->actingAs($user)->getJson(route('api.v1.roles.show', ['role' => self::INVALID_ID]))
-            ->assertNotFound();
+            ->assertNotFound()
+            ->assertJson([
+                'message' => 'model_not_found',
+                'model' => 'role',
+                'ids' => [self::INVALID_ID],
+            ]);
+
         $this->getJson(route('api.v1.roles.show', ['role' => $roleA]))
             ->assertStatus(200)
             ->assertJsonFragment([
@@ -361,7 +378,11 @@ public function test_delete()
         $superuserRole->permissions()->attach($permission->id);
         $role->permissions()->attach($permission->id);
 
-        $this->deleteJson(route('api.v1.roles.destroy', ['role' => self::INVALID_ID]))->assertNotFound();
+        $this->deleteJson(route('api.v1.roles.destroy', ['role' => self::INVALID_ID]))->assertNotFound()->assertJson([
+            'message' => 'model_not_found',
+            'model' => 'role',
+            'ids' => [self::INVALID_ID],
+        ]);
 
         // check if superuser role cannot be deleted
         $this->deleteJson(route('api.v1.roles.destroy', ['role' => $superuserRole]))->assertStatus(403);
diff --git a/tests/Backend/Feature/api/v1/Room/FileTest.php b/tests/Backend/Feature/api/v1/Room/FileTest.php
index f47cdd714..cc9dde46d 100644
--- a/tests/Backend/Feature/api/v1/Room/FileTest.php
+++ b/tests/Backend/Feature/api/v1/Room/FileTest.php
@@ -1085,7 +1085,14 @@ public function test_files_delete()
 
         // Testing delete again
         $this->actingAs($this->room->owner)->deleteJson(route('api.v1.rooms.files.destroy', ['room' => $this->room->id, 'file' => $room_file]))
-            ->assertNotFound();
+            ->assertNotFound()
+            ->assertJson([
+                'message' => 'model_not_found',
+                'model' => 'room_file',
+                'ids' => [
+                    $room_file->id,
+                ],
+            ]);
 
         // Check if file was deleted as well
         Storage::disk('local')->assertMissing($this->room->id.'/'.$this->file_valid->hashName());
@@ -1136,13 +1143,27 @@ public function test_delete_file_url_manipulation()
 
         // Testing for room without permission
         $this->actingAs($this->room->owner)->deleteJson(route('api.v1.rooms.files.destroy', ['room' => $other_room->id, 'file' => $room_file]))
-            ->assertNotFound();
+            ->assertNotFound()
+            ->assertJson([
+                'message' => 'model_not_found',
+                'model' => 'room_file',
+                'ids' => [
+                    $room_file->id,
+                ],
+            ]);
 
         // Testing for room with permission
         $other_room->owner()->associate($this->room->owner);
         $other_room->save();
         $this->actingAs($this->room->owner)->deleteJson(route('api.v1.rooms.files.destroy', ['room' => $other_room->id, 'file' => $room_file]))
-            ->assertNotFound();
+            ->assertNotFound()
+            ->assertJson([
+                'message' => 'model_not_found',
+                'model' => 'room_file',
+                'ids' => [
+                    $room_file->id,
+                ],
+            ]);
     }
 
     /**
@@ -1220,13 +1241,27 @@ public function test_update_file()
         $other_room = Room::factory()->create();
         // Testing for room without permission
         $this->actingAs($this->room->owner)->putJson(route('api.v1.rooms.files.update', ['room' => $other_room->id, 'file' => $room_file]), $params)
-            ->assertNotFound();
+            ->assertNotFound()
+            ->assertJson([
+                'message' => 'model_not_found',
+                'model' => 'room_file',
+                'ids' => [
+                    $room_file->id,
+                ],
+            ]);
 
         // Testing for room with permission
         $other_room->owner()->associate($this->room->owner);
         $other_room->save();
         $this->actingAs($this->room->owner)->putJson(route('api.v1.rooms.files.update', ['room' => $other_room->id, 'file' => $room_file]), $params)
-            ->assertNotFound();
+            ->assertNotFound()
+            ->assertJson([
+                'message' => 'model_not_found',
+                'model' => 'room_file',
+                'ids' => [
+                    $room_file->id,
+                ],
+            ]);
 
         // Testing missing properties
         $params = [];
@@ -1242,6 +1277,31 @@ public function test_update_file()
 
         $this->actingAs($this->room->owner)->putJson($route, $params)
             ->assertJsonValidationErrors(['use_in_meeting', 'download', 'default']);
+
+        // Test deleted
+        $room_file->delete();
+        $this->actingAs($this->room->owner)->putJson($route, $params)
+            ->assertNotFound()
+            ->assertJson([
+                'message' => 'model_not_found',
+                'model' => 'room_file',
+                'ids' => [
+                    $room_file->id,
+                ],
+            ]);
+
+        // Test deleted room
+        $this->room->delete();
+
+        $this->actingAs($this->room->owner)->putJson($route, $params)
+            ->assertNotFound()
+            ->assertJson([
+                'message' => 'model_not_found',
+                'model' => 'room',
+                'ids' => [
+                    $this->room->id,
+                ],
+            ]);
     }
 
     /**
diff --git a/tests/Backend/Feature/api/v1/Room/MembershipTest.php b/tests/Backend/Feature/api/v1/Room/MembershipTest.php
index ee545ee35..3e7d11992 100644
--- a/tests/Backend/Feature/api/v1/Room/MembershipTest.php
+++ b/tests/Backend/Feature/api/v1/Room/MembershipTest.php
@@ -751,54 +751,64 @@ public function test_remove_member()
         $room->members()->attach($memberCoOwner, ['role' => RoomUserRole::CO_OWNER]);
 
         // Remove member as guest
-        $this->deleteJson(route('api.v1.rooms.member.destroy', ['room' => $room, 'user' => $newUser]))
+        $this->deleteJson(route('api.v1.rooms.member.destroy', ['room' => $room, 'member' => $newUser]))
             ->assertUnauthorized();
 
         // Remove member as non owner
-        $this->actingAs($this->user)->deleteJson(route('api.v1.rooms.member.destroy', ['room' => $room, 'user' => $newUser]))
+        $this->actingAs($this->user)->deleteJson(route('api.v1.rooms.member.destroy', ['room' => $room, 'member' => $newUser]))
             ->assertForbidden();
 
         // Remove member as user member
-        $this->actingAs($memberUser)->deleteJson(route('api.v1.rooms.member.destroy', ['room' => $room, 'user' => $newUser]))
+        $this->actingAs($memberUser)->deleteJson(route('api.v1.rooms.member.destroy', ['room' => $room, 'member' => $newUser]))
             ->assertForbidden();
 
         // Remove member as moderator member
-        $this->actingAs($memberModerator)->deleteJson(route('api.v1.rooms.member.destroy', ['room' => $room, 'user' => $newUser]))
+        $this->actingAs($memberModerator)->deleteJson(route('api.v1.rooms.member.destroy', ['room' => $room, 'member' => $newUser]))
             ->assertForbidden();
 
         // Remove member as co-owner member
-        $this->actingAs($memberCoOwner)->deleteJson(route('api.v1.rooms.member.destroy', ['room' => $room, 'user' => $newUser]))
+        $this->actingAs($memberCoOwner)->deleteJson(route('api.v1.rooms.member.destroy', ['room' => $room, 'member' => $newUser]))
             ->assertNoContent();
         $room->members()->attach($newUser, ['role' => RoomUserRole::USER]);
 
         // Remove with view all rooms permission
         $this->user->roles()->attach($this->role);
         $this->role->permissions()->attach($this->viewAllPermission);
-        $this->actingAs($this->user)->deleteJson(route('api.v1.rooms.member.destroy', ['room' => $room, 'user' => $newUser]))
+        $this->actingAs($this->user)->deleteJson(route('api.v1.rooms.member.destroy', ['room' => $room, 'member' => $newUser]))
             ->assertForbidden();
         $this->role->permissions()->detach($this->viewAllPermission);
 
         // Remove with manage rooms permission
         $this->role->permissions()->attach($this->managePermission);
-        $this->actingAs($this->user)->deleteJson(route('api.v1.rooms.member.destroy', ['room' => $room, 'user' => $newUser]))
+        $this->actingAs($this->user)->deleteJson(route('api.v1.rooms.member.destroy', ['room' => $room, 'member' => $newUser]))
             ->assertNoContent();
         $this->role->permissions()->detach($this->managePermission);
         $room->members()->attach($newUser, ['role' => RoomUserRole::USER]);
 
         // Remove member with invalid user
-        $this->actingAs($owner)->deleteJson(route('api.v1.rooms.member.destroy', ['room' => $room, 'user' => 0]))
-            ->assertNotFound();
+        $this->actingAs($owner)->deleteJson(route('api.v1.rooms.member.destroy', ['room' => $room, 'member' => 0]))
+            ->assertNotFound()
+            ->assertJson([
+                'message' => 'model_not_found',
+                'model' => 'user',
+                'ids' => [0],
+            ]);
 
         // Remove member as moderator
-        $this->deleteJson(route('api.v1.rooms.member.destroy', ['room' => $room, 'user' => $newUser]))
+        $this->deleteJson(route('api.v1.rooms.member.destroy', ['room' => $room, 'member' => $newUser]))
             ->assertNoContent();
 
         // Check member list
         $this->assertNull($room->members()->find($newUser));
 
         // Try to remove user again
-        $this->deleteJson(route('api.v1.rooms.member.destroy', ['room' => $room, 'user' => $newUser]))
-            ->assertStatus(410);
+        $this->deleteJson(route('api.v1.rooms.member.destroy', ['room' => $room, 'member' => $newUser]))
+            ->assertNotFound()
+            ->assertJson([
+                'message' => 'model_not_found',
+                'model' => 'user',
+                'ids' => [$newUser->id],
+            ]);
 
         // Check if user is no member
         $this->actingAs($newUser)->getJson(route('api.v1.rooms.show', ['room' => $room]))
@@ -831,45 +841,61 @@ public function test_change_member_role()
         $room->members()->attach($memberCoOwner, ['role' => RoomUserRole::CO_OWNER]);
 
         // Update with wrong role
-        $this->actingAs($owner)->putJson(route('api.v1.rooms.member.update', ['room' => $room, 'user' => $newUser]), ['role' => 10])
+        $this->actingAs($owner)->putJson(route('api.v1.rooms.member.update', ['room' => $room, 'member' => $newUser]), ['role' => 10])
             ->assertJsonValidationErrors(['role']);
 
         // Update role
-        $this->actingAs($owner)->putJson(route('api.v1.rooms.member.update', ['room' => $room, 'user' => $newUser]), ['role' => RoomUserRole::MODERATOR])
+        $this->actingAs($owner)->putJson(route('api.v1.rooms.member.update', ['room' => $room, 'member' => $newUser]), ['role' => RoomUserRole::MODERATOR])
             ->assertNoContent();
 
         // Update role for wrong user
-        $this->actingAs($owner)->putJson(route('api.v1.rooms.member.update', ['room' => $room, 'user' => $otherUser]), ['role' => RoomUserRole::MODERATOR])
-            ->assertStatus(410);
+        $this->actingAs($owner)->putJson(route('api.v1.rooms.member.update', ['room' => $room, 'member' => $otherUser]), ['role' => RoomUserRole::MODERATOR])
+            ->assertNotFound()
+            ->assertJson([
+                'message' => 'model_not_found',
+                'model' => 'user',
+                'ids' => [$otherUser->id],
+            ]);
 
         // Check if member role is changed
         $foundNewUser = $room->members()->find($newUser);
         $this->assertEquals(RoomUserRole::MODERATOR, $foundNewUser->pivot->role);
 
         // Update role as member user
-        $this->actingAs($memberUser)->putJson(route('api.v1.rooms.member.update', ['room' => $room, 'user' => $newUser]), ['role' => RoomUserRole::MODERATOR])
+        $this->actingAs($memberUser)->putJson(route('api.v1.rooms.member.update', ['room' => $room, 'member' => $newUser]), ['role' => RoomUserRole::MODERATOR])
             ->assertForbidden();
 
         // Update role as member moderator
-        $this->actingAs($memberModerator)->putJson(route('api.v1.rooms.member.update', ['room' => $room, 'user' => $newUser]), ['role' => RoomUserRole::MODERATOR])
+        $this->actingAs($memberModerator)->putJson(route('api.v1.rooms.member.update', ['room' => $room, 'member' => $newUser]), ['role' => RoomUserRole::MODERATOR])
             ->assertForbidden();
 
         // Update role as member co-owner
-        $this->actingAs($memberCoOwner)->putJson(route('api.v1.rooms.member.update', ['room' => $room, 'user' => $newUser]), ['role' => RoomUserRole::MODERATOR])
+        $this->actingAs($memberCoOwner)->putJson(route('api.v1.rooms.member.update', ['room' => $room, 'member' => $newUser]), ['role' => RoomUserRole::MODERATOR])
             ->assertNoContent();
 
         // Update role with view all rooms permission
         $this->user->roles()->attach($this->role);
         $this->role->permissions()->attach($this->viewAllPermission);
-        $this->actingAs($this->user)->putJson(route('api.v1.rooms.member.update', ['room' => $room, 'user' => $newUser]), ['role' => RoomUserRole::MODERATOR])
+        $this->actingAs($this->user)->putJson(route('api.v1.rooms.member.update', ['room' => $room, 'member' => $newUser]), ['role' => RoomUserRole::MODERATOR])
             ->assertForbidden();
         $this->role->permissions()->detach($this->viewAllPermission);
 
         // Update role with manage rooms permission
         $this->role->permissions()->attach($this->managePermission);
-        $this->actingAs($this->user)->putJson(route('api.v1.rooms.member.update', ['room' => $room, 'user' => $newUser]), ['role' => RoomUserRole::MODERATOR])
+        $this->actingAs($this->user)->putJson(route('api.v1.rooms.member.update', ['room' => $room, 'member' => $newUser]), ['role' => RoomUserRole::MODERATOR])
             ->assertNoContent();
         $this->role->permissions()->detach($this->managePermission);
+
+        // Test with deleted room
+        $room->delete();
+
+        $this->actingAs($this->user)->putJson(route('api.v1.rooms.member.update', ['room' => $room, 'member' => $newUser]), ['role' => RoomUserRole::MODERATOR])
+            ->assertNotFound()
+            ->assertJson([
+                'message' => 'model_not_found',
+                'model' => 'room',
+                'ids' => [$room->id],
+            ]);
     }
 
     public function test_bulk_import_members()
diff --git a/tests/Backend/Feature/api/v1/Room/RoomDescriptionTest.php b/tests/Backend/Feature/api/v1/Room/RoomDescriptionTest.php
index 490a7891c..e23fc8a6c 100644
--- a/tests/Backend/Feature/api/v1/Room/RoomDescriptionTest.php
+++ b/tests/Backend/Feature/api/v1/Room/RoomDescriptionTest.php
@@ -302,5 +302,16 @@ public function test_update_description_data()
             ->assertUnprocessable();
         $room->refresh();
         $this->assertNull($room->description);
+
+        // Test deleted room
+        $room->delete();
+
+        $this->actingAs($this->user)->putJson(route('api.v1.rooms.description.update', ['room' => $room]), ['description' => $this->faker->text(100)])
+            ->assertNotFound()
+            ->assertJson([
+                'message' => 'model_not_found',
+                'model' => 'room',
+                'ids' => [$room->id],
+            ]);
     }
 }
diff --git a/tests/Backend/Feature/api/v1/Room/RoomPersonalizedLinkTest.php b/tests/Backend/Feature/api/v1/Room/RoomPersonalizedLinkTest.php
index ee9bcb3c1..365f7c2b9 100644
--- a/tests/Backend/Feature/api/v1/Room/RoomPersonalizedLinkTest.php
+++ b/tests/Backend/Feature/api/v1/Room/RoomPersonalizedLinkTest.php
@@ -102,7 +102,12 @@ public function test_index()
 
         // Testing owner
         $this->actingAs($this->room->owner)->getJson(route('api.v1.rooms.personalizedLinks.get', ['room' => 1337]))
-            ->assertNotFound();
+            ->assertNotFound()
+            ->assertJson([
+                'message' => 'model_not_found',
+                'model' => 'room',
+                'ids' => [1337],
+            ]);
 
         $this->actingAs($this->room->owner)->getJson(route('api.v1.rooms.personalizedLinks.get', ['room' => $this->room]))
             ->assertSuccessful()
@@ -252,7 +257,14 @@ public function test_create()
         // Create as moderator
         $this->room->members()->sync([$this->user->id => ['role' => RoomUserRole::MODERATOR]]);
         $this->actingAs($this->user)->postJson(route('api.v1.rooms.personalizedLinks.add', ['room' => 1337]), $payload)
-            ->assertNotFound();
+            ->assertNotFound()
+            ->assertJson(
+                [
+                    'message' => 'model_not_found',
+                    'model' => 'room',
+                    'ids' => [1337],
+                ]
+            );
         $this->actingAs($this->user)->postJson(route('api.v1.rooms.personalizedLinks.add', ['room' => $this->room]), $payload)
             ->assertForbidden();
 
@@ -320,7 +332,7 @@ public function test_update()
         ];
 
         // Update as guest
-        $this->putJson(route('api.v1.rooms.personalizedLinks.update', ['room' => $this->room, 'link' => $link]), $payload)
+        $this->putJson(route('api.v1.rooms.personalizedLinks.update', ['room' => $this->room, 'personalizedLink' => $link]), $payload)
             ->assertUnauthorized()
             ->assertJsonFragment(['message' => 'Unauthenticated.']);
 
@@ -336,7 +348,7 @@ public function test_update()
 
         $this->putJson(route('api.v1.rooms.personalizedLinks.update', [
             'room' => $this->room,
-            'link' => $link,
+            'personalizedLink' => $link,
             'room_auth_token' => $roomAuthToken->id,
             'room_auth_token_type' => RoomAuthTokenType::PERSONALIZED_LINK->value,
         ]), $payload)
@@ -345,14 +357,21 @@ public function test_update()
 
         // Update as moderator
         $this->room->members()->sync([$this->user->id => ['role' => RoomUserRole::MODERATOR]]);
-        $this->actingAs($this->user)->putJson(route('api.v1.rooms.personalizedLinks.update', ['room' => 1337, 'link' => $link]), $payload)
-            ->assertNotFound();
-        $this->actingAs($this->user)->putJson(route('api.v1.rooms.personalizedLinks.update', ['room' => $this->room, 'link' => $link]), $payload)
+        $this->actingAs($this->user)->putJson(route('api.v1.rooms.personalizedLinks.update', ['room' => 1337, 'personalizedLink' => $link]), $payload)
+            ->assertNotFound()
+            ->assertJson(
+                [
+                    'message' => 'model_not_found',
+                    'model' => 'room',
+                    'ids' => [1337],
+                ]);
+
+        $this->actingAs($this->user)->putJson(route('api.v1.rooms.personalizedLinks.update', ['room' => $this->room, 'personalizedLink' => $link]), $payload)
             ->assertForbidden();
 
         // Update as co-owner invalid data
         $this->room->members()->sync([$this->user->id => ['role' => RoomUserRole::CO_OWNER]]);
-        $this->actingAs($this->user)->putJson(route('api.v1.rooms.personalizedLinks.update', ['room' => $this->room, 'link' => $link]), $payload)
+        $this->actingAs($this->user)->putJson(route('api.v1.rooms.personalizedLinks.update', ['room' => $this->room, 'personalizedLink' => $link]), $payload)
             ->assertJsonValidationErrors([
                 'firstname',
                 'lastname',
@@ -365,7 +384,7 @@ public function test_update()
             'lastname' => $this->faker->lastName,
             'role' => RoomUserRole::USER,
         ];
-        $response = $this->actingAs($this->user)->putJson(route('api.v1.rooms.personalizedLinks.update', ['room' => $this->room, 'link' => $link]), $payload)
+        $response = $this->actingAs($this->user)->putJson(route('api.v1.rooms.personalizedLinks.update', ['room' => $this->room, 'personalizedLink' => $link]), $payload)
             ->assertSuccessful()
             ->assertJsonMissingValidationErrors([
                 'firstname',
@@ -380,7 +399,7 @@ public function test_update()
             'lastname' => $this->faker->lastName,
             'role' => RoomUserRole::USER,
         ];
-        $response = $this->actingAs($this->room->owner)->putJson(route('api.v1.rooms.personalizedLinks.update', ['room' => $this->room, 'link' => $link]), $payload)
+        $response = $this->actingAs($this->room->owner)->putJson(route('api.v1.rooms.personalizedLinks.update', ['room' => $this->room, 'personalizedLink' => $link]), $payload)
             ->assertSuccessful()
             ->assertJsonMissingValidationErrors([
                 'firstname',
@@ -397,7 +416,7 @@ public function test_update()
         ];
         $this->room->members()->sync([]);
         $this->user->roles()->attach(Role::where(['superuser' => true])->first());
-        $response = $this->actingAs($this->user)->putJson(route('api.v1.rooms.personalizedLinks.update', ['room' => $this->room, 'link' => $link]), $payload)
+        $this->actingAs($this->user)->putJson(route('api.v1.rooms.personalizedLinks.update', ['room' => $this->room, 'personalizedLink' => $link]), $payload)
             ->assertSuccessful()
             ->assertJsonMissingValidationErrors([
                 'firstname',
@@ -406,8 +425,37 @@ public function test_update()
             ]);
 
         // Check trying to update with wrong room id
-        $this->actingAs($this->user)->putJson(route('api.v1.rooms.personalizedLinks.update', ['room' => $otherRoom, 'link' => $link]), $payload)
-            ->assertNotFound();
+        $this->actingAs($this->user)->putJson(route('api.v1.rooms.personalizedLinks.update', ['room' => $otherRoom, 'personalizedLink' => $link]), $payload)
+            ->assertNotFound()
+            ->assertJson(
+                [
+                    'message' => 'model_not_found',
+                    'model' => 'room_personalized_link',
+                    'ids' => [$link->id],
+                ]);
+
+        // Test deleted
+        $link->delete();
+        $this->actingAs($this->user)->putJson(route('api.v1.rooms.personalizedLinks.update', ['room' => $this->room, 'personalizedLink' => $link]), $payload)
+            ->assertNotFound()
+            ->assertJson(
+                [
+                    'message' => 'model_not_found',
+                    'model' => 'room_personalized_link',
+                    'ids' => [$link->id],
+                ]);
+
+        // Test deleted room
+        $this->room->delete();
+
+        $this->actingAs($this->user)->putJson(route('api.v1.rooms.personalizedLinks.update', ['room' => $this->room, 'personalizedLink' => $link]), $payload)
+            ->assertNotFound()
+            ->assertJson(
+                [
+                    'message' => 'model_not_found',
+                    'model' => 'room',
+                    'ids' => [$this->room->id],
+                ]);
     }
 
     public function test_delete()
@@ -423,7 +471,7 @@ public function test_delete()
         ]);
 
         // Delete as guest
-        $this->deleteJson(route('api.v1.rooms.personalizedLinks.destroy', ['room' => $this->room, 'link' => $link]))
+        $this->deleteJson(route('api.v1.rooms.personalizedLinks.destroy', ['room' => $this->room, 'personalizedLink' => $link]))
             ->assertUnauthorized()
             ->assertJsonFragment(['message' => 'Unauthenticated.']);
 
@@ -439,7 +487,7 @@ public function test_delete()
 
         $this->deleteJson(route('api.v1.rooms.personalizedLinks.destroy', [
             'room' => $this->room,
-            'link' => $link,
+            'personalizedLink' => $link,
             'room_auth_token' => $roomAuthToken->id,
             'room_auth_token_type' => RoomAuthTokenType::PERSONALIZED_LINK->value,
         ]))
@@ -448,26 +496,38 @@ public function test_delete()
 
         // Delete as moderator
         $this->room->members()->sync([$this->user->id => ['role' => RoomUserRole::MODERATOR]]);
-        $this->actingAs($this->user)->deleteJson(route('api.v1.rooms.personalizedLinks.destroy', ['room' => $this->room, 'link' => $link]))
+        $this->actingAs($this->user)->deleteJson(route('api.v1.rooms.personalizedLinks.destroy', ['room' => $this->room, 'personalizedLink' => $link]))
             ->assertForbidden();
 
         // Delete as co-owner
         $this->room->members()->sync([$this->user->id => ['role' => RoomUserRole::CO_OWNER]]);
-        $this->actingAs($this->user)->deleteJson(route('api.v1.rooms.personalizedLinks.destroy', ['room' => $this->room, 'link' => $link]))
+        $this->actingAs($this->user)->deleteJson(route('api.v1.rooms.personalizedLinks.destroy', ['room' => $this->room, 'personalizedLink' => $link]))
             ->assertSuccessful();
 
         // Delete not existing
-        $this->actingAs($this->user)->deleteJson(route('api.v1.rooms.personalizedLinks.destroy', ['room' => $this->room, 'link' => $link]))
-            ->assertNotFound();
+        $this->actingAs($this->user)->deleteJson(route('api.v1.rooms.personalizedLinks.destroy', ['room' => $this->room, 'personalizedLink' => $link]))
+            ->assertNotFound()
+            ->assertJson(
+                [
+                    'message' => 'model_not_found',
+                    'model' => 'room_personalized_link',
+                    'ids' => [$link->id],
+                ]);
 
         // Delete as owner
         $link = RoomPersonalizedLink::factory()->create([
             'room_id' => $this->room,
         ]);
-        $this->actingAs($this->room->owner)->deleteJson(route('api.v1.rooms.personalizedLinks.destroy', ['room' => $this->room, 'link' => $link]))
+        $this->actingAs($this->room->owner)->deleteJson(route('api.v1.rooms.personalizedLinks.destroy', ['room' => $this->room, 'personalizedLink' => $link]))
             ->assertSuccessful();
-        $this->actingAs($this->room->owner)->deleteJson(route('api.v1.rooms.personalizedLinks.destroy', ['room' => $this->room, 'link' => $link]))
-            ->assertNotFound();
+        $this->actingAs($this->room->owner)->deleteJson(route('api.v1.rooms.personalizedLinks.destroy', ['room' => $this->room, 'personalizedLink' => $link]))
+            ->assertNotFound()
+            ->assertJson(
+                [
+                    'message' => 'model_not_found',
+                    'model' => 'room_personalized_link',
+                    'ids' => [$link->id],
+                ]);
 
         // Delete with viewAllPermission
         $this->room->members()->sync([]);
@@ -477,12 +537,26 @@ public function test_delete()
         ]);
 
         // Check trying to delete with wrong room id
-        $this->actingAs($this->user)->deleteJson(route('api.v1.rooms.personalizedLinks.destroy', ['room' => $otherRoom, 'link' => $link]))
-            ->assertNotFound();
-
-        $this->actingAs($this->user)->deleteJson(route('api.v1.rooms.personalizedLinks.destroy', ['room' => $this->room, 'link' => $link]))
+        $this->actingAs($this->user)->deleteJson(route('api.v1.rooms.personalizedLinks.destroy', ['room' => $otherRoom, 'personalizedLink' => $link]))
+            ->assertNotFound()
+            ->assertJson(
+                [
+                    'message' => 'model_not_found',
+                    'model' => 'room_personalized_link',
+                    'ids' => [$link->id],
+                ]);
+
+        $this->actingAs($this->user)->deleteJson(route('api.v1.rooms.personalizedLinks.destroy', ['room' => $this->room, 'personalizedLink' => $link]))
             ->assertSuccessful();
-        $this->actingAs($this->user)->deleteJson(route('api.v1.rooms.personalizedLinks.destroy', ['room' => $this->room, 'link' => $link]))
-            ->assertNotFound();
+
+        // Test delete again
+        $this->actingAs($this->user)->deleteJson(route('api.v1.rooms.personalizedLinks.destroy', ['room' => $this->room, 'personalizedLink' => $link]))
+            ->assertNotFound()
+            ->assertJson(
+                [
+                    'message' => 'model_not_found',
+                    'model' => 'room_personalized_link',
+                    'ids' => [$link->id],
+                ]);
     }
 }
diff --git a/tests/Backend/Feature/api/v1/Room/RoomTest.php b/tests/Backend/Feature/api/v1/Room/RoomTest.php
index 85e6647de..f871656ca 100644
--- a/tests/Backend/Feature/api/v1/Room/RoomTest.php
+++ b/tests/Backend/Feature/api/v1/Room/RoomTest.php
@@ -292,7 +292,12 @@ public function test_delete_room()
 
         // Try again after deleted
         $this->actingAs($this->user)->deleteJson(route('api.v1.rooms.destroy', ['room' => $room]))
-            ->assertNotFound();
+            ->assertNotFound()
+            ->assertJson([
+                'message' => 'model_not_found',
+                'model' => 'room',
+                'ids' => [$room->id],
+            ]);
     }
 
     public function test_transfer_room()
@@ -433,7 +438,12 @@ public function test_room_404_rate_limit()
         // Guest trying to access non-existing rooms
         for ($i = 0; $i < 10; $i++) {
             $this->getJson(route('api.v1.rooms.show', ['room' => 999999]))
-                ->assertNotFound();
+                ->assertNotFound()
+                ->assertJson([
+                    'message' => 'model_not_found',
+                    'model' => 'room',
+                    'ids' => [999999],
+                ]);
         }
         // Check route is now rate limited
         $this->getJson(route('api.v1.rooms.show', ['room' => 999999]))
@@ -448,7 +458,12 @@ public function test_room_404_rate_limit()
         $this->actingAs($room->owner);
         for ($i = 0; $i < 10; $i++) {
             $this->getJson(route('api.v1.rooms.show', ['room' => 999999]))
-                ->assertNotFound();
+                ->assertNotFound()
+                ->assertJson([
+                    'message' => 'model_not_found',
+                    'model' => 'room',
+                    'ids' => [999999],
+                ]);
         }
         // Check route is now rate limited
         $this->getJson(route('api.v1.rooms.show', ['room' => 999999]))
@@ -464,11 +479,21 @@ public function test_room_404_rate_limit()
         // Time travel 1 minute to reset rate limit
         $this->travel(1)->minutes();
         $this->getJson(route('api.v1.rooms.show', ['room' => 999999]))
-            ->assertNotFound();
+            ->assertNotFound()
+            ->assertJson([
+                'message' => 'model_not_found',
+                'model' => 'room',
+                'ids' => [999999],
+            ]);
 
         $this->actingAsGuest();
         $this->getJson(route('api.v1.rooms.show', ['room' => 999999]))
-            ->assertNotFound();
+            ->assertNotFound()
+            ->assertJson([
+                'message' => 'model_not_found',
+                'model' => 'room',
+                'ids' => [999999],
+            ]);
 
         // Time travel 1 minute to reset rate limit
         $this->travel(1)->minutes();
@@ -477,7 +502,12 @@ public function test_room_404_rate_limit()
         // due to other reasons than the room not existing are not so strictly rate limited
         for ($i = 0; $i < 50; $i++) {
             $this->actingAs($room->owner)->putJson(route('api.v1.rooms.files.update', ['room' => $room, 'file' => 999999]))
-                ->assertNotFound();
+                ->assertNotFound()
+                ->assertJson([
+                    'message' => 'model_not_found',
+                    'model' => 'room_file',
+                    'ids' => ['999999'],
+                ]);
         }
     }
 
@@ -1639,6 +1669,17 @@ public function test_room_view()
         $room->save();
         $this->actingAs($this->user)->getJson(route('api.v1.rooms.show', ['room' => $room]))
             ->assertJsonPath('data.legacy_code', false);
+
+        // Test deleted
+        $room->delete();
+
+        $this->actingAs($this->user)->getJson(route('api.v1.rooms.show', ['room' => $room]))
+            ->assertNotFound()
+            ->assertJson([
+                'message' => 'model_not_found',
+                'model' => 'room',
+                'ids' => [$room->id],
+            ]);
     }
 
     /**
diff --git a/tests/Backend/Feature/api/v1/RoomTypeTest.php b/tests/Backend/Feature/api/v1/RoomTypeTest.php
index eb8bfce22..53ecda1ae 100644
--- a/tests/Backend/Feature/api/v1/RoomTypeTest.php
+++ b/tests/Backend/Feature/api/v1/RoomTypeTest.php
@@ -327,7 +327,14 @@ public function test_show()
         // Test deleted
         $roomType->delete();
         $this->actingAs($this->user)->getJson(route('api.v1.roomTypes.show', ['roomType' => $roomType->id]))
-            ->assertNotFound();
+            ->assertNotFound()
+            ->assertJson([
+                'message' => 'model_not_found',
+                'model' => 'room_type',
+                'ids' => [
+                    $roomType->id,
+                ],
+            ]);
     }
 
     /**
@@ -897,7 +904,14 @@ public function test_update()
         // Test deleted
         $roomType->delete();
         $this->actingAs($this->user)->putJson(route('api.v1.roomTypes.update', ['roomType' => $roomType->id]), $data)
-            ->assertNotFound();
+            ->assertNotFound()
+            ->assertJson([
+                'message' => 'model_not_found',
+                'model' => 'room_type',
+                'ids' => [
+                    $roomType->id,
+                ],
+            ]);
     }
 
     /**
@@ -927,7 +941,14 @@ public function test_delete()
 
         // Test delete again
         $this->actingAs($this->user)->deleteJson(route('api.v1.roomTypes.destroy', ['roomType' => $roomType->id]))
-            ->assertNotFound();
+            ->assertNotFound()
+            ->assertJson([
+                'message' => 'model_not_found',
+                'model' => 'room_type',
+                'ids' => [
+                    $roomType->id,
+                ],
+            ]);
 
         $this->assertDatabaseMissing('room_types', ['id' => $roomType->id]);
 
diff --git a/tests/Backend/Feature/api/v1/ServerPoolTest.php b/tests/Backend/Feature/api/v1/ServerPoolTest.php
index 85806a78a..60969dba9 100644
--- a/tests/Backend/Feature/api/v1/ServerPoolTest.php
+++ b/tests/Backend/Feature/api/v1/ServerPoolTest.php
@@ -176,7 +176,14 @@ public function test_show()
         // Test deleted
         $serverPool->delete();
         $this->actingAs($this->user)->getJson(route('api.v1.serverPools.show', ['serverPool' => $serverPool->id]))
-            ->assertNotFound();
+            ->assertNotFound()
+            ->assertJson([
+                'message' => 'model_not_found',
+                'model' => 'server_pool',
+                'ids' => [
+                    $serverPool->id,
+                ],
+            ]);
     }
 
     /**
@@ -342,7 +349,14 @@ public function test_update()
         // Test deleted
         $serverPool->delete();
         $this->actingAs($this->user)->putJson(route('api.v1.serverPools.update', ['serverPool' => $serverPool->id]), $data)
-            ->assertNotFound();
+            ->assertNotFound()
+            ->assertJson([
+                'message' => 'model_not_found',
+                'model' => 'server_pool',
+                'ids' => [
+                    $serverPool->id,
+                ],
+            ]);
     }
 
     /**
@@ -381,7 +395,14 @@ public function test_delete()
 
         // Test delete again
         $this->actingAs($this->user)->deleteJson(route('api.v1.serverPools.destroy', ['serverPool' => $serverPool->id]))
-            ->assertNotFound();
+            ->assertNotFound()
+            ->assertJson([
+                'message' => 'model_not_found',
+                'model' => 'server_pool',
+                'ids' => [
+                    $serverPool->id,
+                ],
+            ]);
 
         $this->assertDatabaseMissing('servers', ['id' => $serverPool->id]);
     }
diff --git a/tests/Backend/Feature/api/v1/ServerTest.php b/tests/Backend/Feature/api/v1/ServerTest.php
index 4c6c722e3..cb958635b 100644
--- a/tests/Backend/Feature/api/v1/ServerTest.php
+++ b/tests/Backend/Feature/api/v1/ServerTest.php
@@ -250,7 +250,12 @@ public function test_show()
         $server->save();
         $server->delete();
         $this->actingAs($this->user)->getJson(route('api.v1.servers.show', ['server' => $server->id]))
-            ->assertNotFound();
+            ->assertNotFound()
+            ->assertJson([
+                'message' => 'model_not_found',
+                'model' => 'server',
+                'ids' => [$server->id],
+            ]);
     }
 
     /**
@@ -401,7 +406,12 @@ public function test_update()
         $server->save();
         $server->delete();
         $this->actingAs($this->user)->putJson(route('api.v1.servers.update', ['server' => $server->id]), $data)
-            ->assertNotFound();
+            ->assertNotFound()
+            ->assertJson([
+                'message' => 'model_not_found',
+                'model' => 'server',
+                'ids' => [$server->id],
+            ]);
     }
 
     /**
@@ -450,7 +460,12 @@ public function test_delete()
 
         // Test delete again
         $this->actingAs($this->user)->deleteJson(route('api.v1.servers.destroy', ['server' => $server->id]))
-            ->assertNotFound();
+            ->assertNotFound()
+            ->assertJson([
+                'message' => 'model_not_found',
+                'model' => 'server',
+                'ids' => [$server->id],
+            ]);
 
         $this->assertDatabaseMissing('servers', ['id' => $server->id]);
     }
@@ -553,5 +568,22 @@ public function test_panic()
 
         $this->assertEquals(ServerStatus::DISABLED, $server->status);
         $this->assertNull($meeting->end);
+
+        // Test deleted
+        $server->status = ServerStatus::DISABLED;
+        $server->save();
+
+        $meeting->end = date('Y-m-d H:i:s');
+        $meeting->save();
+
+        $server->delete();
+
+        $this->actingAs($this->user)->postJson(route('api.v1.servers.panic', ['server' => $server->id]))
+            ->assertNotFound()
+            ->assertJson([
+                'message' => 'model_not_found',
+                'model' => 'server',
+                'ids' => [$server->id],
+            ]);
     }
 }
diff --git a/tests/Backend/Feature/api/v1/UserTest.php b/tests/Backend/Feature/api/v1/UserTest.php
index a85462cf8..12e4ad94a 100644
--- a/tests/Backend/Feature/api/v1/UserTest.php
+++ b/tests/Backend/Feature/api/v1/UserTest.php
@@ -533,7 +533,13 @@ public function test_update()
 
         // Not existing user
         $this->actingAs($admin)->putJson(route('api.v1.users.update', ['user' => self::INVALID_ID]), $changes)
-            ->assertNotFound();
+            ->assertNotFound()
+            ->assertJson([
+                'message' => 'model_not_found',
+                'model' => 'user',
+                'ids' => [self::INVALID_ID],
+            ]
+            );
 
         // Check as admin
         $changes['updated_at'] = Carbon::now();
@@ -1413,7 +1419,12 @@ public function test_show()
         $role->users()->attach([$externalUser->id, $user->id]);
 
         $this->actingAs($user)->getJson(route('api.v1.users.show', ['user' => self::INVALID_ID]))
-            ->assertNotFound();
+            ->assertNotFound()
+            ->assertJson([
+                'message' => 'model_not_found',
+                'model' => 'user',
+                'ids' => [self::INVALID_ID],
+            ]);
 
         // Existing user
         $this->actingAs($user)->getJson(route('api.v1.users.show', ['user' => $externalUser]))
@@ -1477,7 +1488,12 @@ public function test_delete()
             ->assertForbidden();
 
         // Not existing model
-        $this->actingAs($user)->deleteJson(route('api.v1.users.destroy', ['user' => self::INVALID_ID]))->assertNotFound();
+        $this->actingAs($user)->deleteJson(route('api.v1.users.destroy', ['user' => self::INVALID_ID]))->assertNotFound()
+            ->assertJson([
+                'message' => 'model_not_found',
+                'model' => 'user',
+                'ids' => [self::INVALID_ID],
+            ]);
 
         // User own model
         $this->actingAs($user)->deleteJson(route('api.v1.users.destroy', ['user' => $user]))
@@ -1556,7 +1572,12 @@ public function test_reset_password()
         $role->users()->attach([$user->id]);
 
         $this->actingAs($user)->postJson(route('api.v1.users.password.reset', ['user' => self::INVALID_ID]))
-            ->assertNotFound();
+            ->assertNotFound()
+            ->assertJson([
+                'message' => 'model_not_found',
+                'model' => 'user',
+                'ids' => [self::INVALID_ID],
+            ]);
 
         $this->actingAs($user)->postJson(route('api.v1.users.password.reset', ['user' => $user]))
             ->assertForbidden();
diff --git a/tests/Frontend/e2e/AdminRolesEdit.cy.js b/tests/Frontend/e2e/AdminRolesEdit.cy.js
index 6aeb1e919..0d0a53e6b 100644
--- a/tests/Frontend/e2e/AdminRolesEdit.cy.js
+++ b/tests/Frontend/e2e/AdminRolesEdit.cy.js
@@ -1629,7 +1629,9 @@ describe("Admin roles edit", function () {
     cy.intercept("PUT", "api/v1/roles/2", {
       statusCode: 404,
       body: {
-        message: "No query results for model",
+        message: "model_not_found",
+        model: "role",
+        ids: [2],
       },
     }).as("saveChangesRequest");
 
@@ -1644,8 +1646,8 @@ describe("Admin roles edit", function () {
     cy.wait("@rolesRequest");
 
     cy.checkToastMessage([
-      'app.flash.server_error.message_{"message":"No query results for model"}',
-      'app.flash.server_error.error_code_{"statusCode":404}',
+      'app.flash.model_not_found.title_{"model":"app.model.role"}',
+      'app.flash.model_not_found.details_{"ids":"2"}',
     ]);
 
     // Reload
@@ -1792,7 +1794,9 @@ describe("Admin roles edit", function () {
     cy.intercept("GET", "api/v1/roles/2", {
       statusCode: 404,
       body: {
-        message: "No query results for model",
+        message: "model_not_found",
+        model: "role",
+        ids: [2],
       },
     }).as("roleRequest");
 
@@ -1809,8 +1813,8 @@ describe("Admin roles edit", function () {
 
     // Check that error message is shown
     cy.checkToastMessage([
-      'app.flash.server_error.message_{"message":"No query results for model"}',
-      'app.flash.server_error.error_code_{"statusCode":404}',
+      'app.flash.model_not_found.title_{"model":"app.model.role"}',
+      'app.flash.model_not_found.details_{"ids":"2"}',
     ]);
 
     // Reload page with 401 error
diff --git a/tests/Frontend/e2e/AdminRolesIndexRoleActions.cy.js b/tests/Frontend/e2e/AdminRolesIndexRoleActions.cy.js
index e7bb1f004..c149da653 100644
--- a/tests/Frontend/e2e/AdminRolesIndexRoleActions.cy.js
+++ b/tests/Frontend/e2e/AdminRolesIndexRoleActions.cy.js
@@ -162,8 +162,55 @@ describe("Admin roles index role actions", function () {
       'app.flash.server_error.error_code_{"statusCode":464}',
     ]);
 
-    // Check with 401 error
+    // Check with 404 error
+    cy.fixture("roles.json").then((roles) => {
+      roles.data = roles.data.filter((role) => role.id !== 3);
+      roles.meta.to = 2;
+      roles.meta.total = 2;
+      roles.meta.total_no_filter = 2;
+
+      cy.intercept("GET", "api/v1/roles*", {
+        statusCode: 200,
+        body: roles,
+      }).as("rolesRequest");
+    });
+
     cy.intercept("DELETE", "api/v1/roles/3", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "role",
+        ids: [3],
+      },
+    }).as("deleteRoleRequest");
+
+    cy.get('[data-test="dialog-continue-button"]').click();
+
+    cy.wait("@deleteRoleRequest");
+
+    // Check that role list was refreshed
+    cy.wait("@rolesRequest");
+
+    // Check that dialog is closed and that error message is shown
+    cy.get('[data-test="roles-delete-dialog"]').should("not.exist");
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.role"}',
+      'app.flash.model_not_found.details_{"ids":"3"}',
+    ]);
+
+    // Check that role is not in the list anymore
+    cy.get('[data-test="role-item"]').should("have.length", 2);
+
+    // Reopen dialog for different role
+    cy.get('[data-test="role-item"]')
+      .eq(1)
+      .find('[data-test="roles-delete-button"]')
+      .click();
+
+    cy.get('[data-test="roles-delete-dialog"]').should("be.visible");
+
+    // Check with 401 error
+    cy.intercept("DELETE", "api/v1/roles/2", {
       statusCode: 401,
     }).as("deleteRoleRequest");
 
diff --git a/tests/Frontend/e2e/AdminRolesView.cy.js b/tests/Frontend/e2e/AdminRolesView.cy.js
index 726a7a879..7b1a9a048 100644
--- a/tests/Frontend/e2e/AdminRolesView.cy.js
+++ b/tests/Frontend/e2e/AdminRolesView.cy.js
@@ -680,7 +680,9 @@ describe("Admin roles view", function () {
     cy.intercept("GET", "api/v1/roles/2", {
       statusCode: 404,
       body: {
-        message: "No query results for model",
+        message: "model_not_found",
+        model: "role",
+        ids: [2],
       },
     }).as("roleRequest");
 
@@ -697,8 +699,8 @@ describe("Admin roles view", function () {
 
     // Check that error message is shown
     cy.checkToastMessage([
-      'app.flash.server_error.message_{"message":"No query results for model"}',
-      'app.flash.server_error.error_code_{"statusCode":404}',
+      'app.flash.model_not_found.title_{"model":"app.model.role"}',
+      'app.flash.model_not_found.details_{"ids":"2"}',
     ]);
 
     // Reload page with 401 error
diff --git a/tests/Frontend/e2e/AdminRolesViewRoleActions.cy.js b/tests/Frontend/e2e/AdminRolesViewRoleActions.cy.js
index 0f4f99da8..c5e81c696 100644
--- a/tests/Frontend/e2e/AdminRolesViewRoleActions.cy.js
+++ b/tests/Frontend/e2e/AdminRolesViewRoleActions.cy.js
@@ -137,6 +137,37 @@ describe("Admin roles view role actions", function () {
       'app.flash.server_error.error_code_{"statusCode":464}',
     ]);
 
+    // Check with 404 error
+    cy.intercept("DELETE", "api/v1/roles/2", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "role",
+        ids: [2],
+      },
+    }).as("deleteRoleRequest");
+
+    cy.interceptAdminRolesIndexRequests();
+
+    cy.get('[data-test="dialog-continue-button"]').click();
+
+    cy.wait("@deleteRoleRequest");
+
+    // Check that redirect worked and error message is shown
+    cy.url().should("include", "/admin/roles").and("not.include", "/2");
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.role"}',
+      'app.flash.model_not_found.details_{"ids":"2"}',
+    ]);
+
+    // Reload view and open delete dialog again
+    cy.visit("/admin/roles/2");
+
+    cy.wait("@roleRequest");
+
+    cy.get('[data-test="roles-delete-button"]').click();
+    cy.get('[data-test="roles-delete-dialog"]').should("be.visible");
+
     // Check with 401 error
     cy.intercept("DELETE", "api/v1/roles/2", {
       statusCode: 401,
diff --git a/tests/Frontend/e2e/AdminRoomTypesEdit.cy.js b/tests/Frontend/e2e/AdminRoomTypesEdit.cy.js
index cf8d54a87..034cb4f55 100644
--- a/tests/Frontend/e2e/AdminRoomTypesEdit.cy.js
+++ b/tests/Frontend/e2e/AdminRoomTypesEdit.cy.js
@@ -2067,7 +2067,9 @@ describe("Admin room types edit", function () {
     cy.intercept("PUT", "api/v1/roomTypes/3", {
       statusCode: 404,
       body: {
-        message: "No query results for model",
+        message: "model_not_found",
+        model: "room_type",
+        ids: [3],
       },
     }).as("saveChangesRequest");
 
@@ -2082,8 +2084,8 @@ describe("Admin room types edit", function () {
     cy.wait("@roomTypesRequest");
 
     cy.checkToastMessage([
-      'app.flash.server_error.message_{"message":"No query results for model"}',
-      'app.flash.server_error.error_code_{"statusCode":404}',
+      'app.flash.model_not_found.title_{"model":"app.model.room_type"}',
+      'app.flash.model_not_found.details_{"ids":"3"}',
     ]);
 
     // Reload
@@ -2148,7 +2150,9 @@ describe("Admin room types edit", function () {
     cy.intercept("GET", "api/v1/roomTypes/3", {
       statusCode: 404,
       body: {
-        message: "No query results for model",
+        message: "model_not_found",
+        model: "room_type",
+        ids: [3],
       },
     }).as("roomTypeRequest");
 
@@ -2163,8 +2167,8 @@ describe("Admin room types edit", function () {
     cy.wait("@roomTypesRequest");
 
     cy.checkToastMessage([
-      'app.flash.server_error.message_{"message":"No query results for model"}',
-      'app.flash.server_error.error_code_{"statusCode":404}',
+      'app.flash.model_not_found.title_{"model":"app.model.room_type"}',
+      'app.flash.model_not_found.details_{"ids":"3"}',
     ]);
 
     // Reload page with 401 error
diff --git a/tests/Frontend/e2e/AdminRoomTypesIndexRoomTypeActions.cy.js b/tests/Frontend/e2e/AdminRoomTypesIndexRoomTypeActions.cy.js
index 00ba597ad..332e4e44a 100644
--- a/tests/Frontend/e2e/AdminRoomTypesIndexRoomTypeActions.cy.js
+++ b/tests/Frontend/e2e/AdminRoomTypesIndexRoomTypeActions.cy.js
@@ -340,7 +340,9 @@ describe("Admin room types index room type actions", function () {
     cy.intercept("DELETE", "api/v1/roomTypes/3", {
       statusCode: 404,
       body: {
-        message: "No query results for model",
+        message: "model_not_found",
+        model: "room_type",
+        ids: [3],
       },
     }).as("deleteRoomTypeRequest");
 
@@ -356,8 +358,8 @@ describe("Admin room types index room type actions", function () {
 
     // Check that error message is shown
     cy.checkToastMessage([
-      'app.flash.server_error.message_{"message":"No query results for model"}',
-      'app.flash.server_error.error_code_{"statusCode":404}',
+      'app.flash.model_not_found.title_{"model":"app.model.room_type"}',
+      'app.flash.model_not_found.details_{"ids":"3"}',
     ]);
 
     // Check that room type is not there anymore
@@ -369,6 +371,7 @@ describe("Admin room types index room type actions", function () {
       .eq(1)
       .should("include.text", "Meeting");
 
+    // Reopen dialog for different room type
     cy.get('[data-test="room-type-item"]')
       .eq(0)
       .find('[data-test="room-types-delete-button"]')
diff --git a/tests/Frontend/e2e/AdminRoomTypesView.cy.js b/tests/Frontend/e2e/AdminRoomTypesView.cy.js
index 3ec2cd60f..fddec5bab 100644
--- a/tests/Frontend/e2e/AdminRoomTypesView.cy.js
+++ b/tests/Frontend/e2e/AdminRoomTypesView.cy.js
@@ -631,7 +631,9 @@ describe("Admin room types view", function () {
     cy.intercept("GET", "api/v1/roomTypes/3", {
       statusCode: 404,
       body: {
-        message: "No query results for model",
+        message: "model_not_found",
+        model: "room_type",
+        ids: [3],
       },
     }).as("roomTypeRequest");
 
@@ -647,8 +649,8 @@ describe("Admin room types view", function () {
 
     // Check that error message is shown
     cy.checkToastMessage([
-      'app.flash.server_error.message_{"message":"No query results for model"}',
-      'app.flash.server_error.error_code_{"statusCode":404}',
+      'app.flash.model_not_found.title_{"model":"app.model.room_type"}',
+      'app.flash.model_not_found.details_{"ids":"3"}',
     ]);
 
     // Reload page with 401 error
diff --git a/tests/Frontend/e2e/AdminRoomTypesViewRoomTypeActions.cy.js b/tests/Frontend/e2e/AdminRoomTypesViewRoomTypeActions.cy.js
index 6234d50dd..1a739b263 100644
--- a/tests/Frontend/e2e/AdminRoomTypesViewRoomTypeActions.cy.js
+++ b/tests/Frontend/e2e/AdminRoomTypesViewRoomTypeActions.cy.js
@@ -287,6 +287,38 @@ describe("Admin room types view room type actions", function () {
       "Replacement room type required! Rooms are still assigned to this room type.",
     );
 
+    // Check with 404 error
+    cy.intercept("DELETE", "api/v1/roomTypes/3", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "room_type",
+        ids: [3],
+      },
+    }).as("deleteRoomTypeRequest");
+
+    cy.interceptAdminRoomTypesIndexRequests();
+
+    cy.get('[data-test="dialog-continue-button"]').click();
+
+    cy.wait("@deleteRoomTypeRequest");
+
+    // Check that redirect worked and error message is shown
+    cy.url().should("include", "/admin/room_types").and("not.include", "/3");
+
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room_type"}',
+      'app.flash.model_not_found.details_{"ids":"3"}',
+    ]);
+
+    // Reload view and open delete dialog again
+    cy.visit("/admin/room_types/3");
+
+    cy.wait("@roomTypeRequest");
+
+    cy.get('[data-test="room-types-delete-button"]').click();
+    cy.get('[data-test="room-types-delete-dialog"]').should("be.visible");
+
     // Check with 401 error
     cy.intercept("DELETE", "api/v1/roomTypes/3", {
       statusCode: 401,
diff --git a/tests/Frontend/e2e/AdminServerPoolsEdit.cy.js b/tests/Frontend/e2e/AdminServerPoolsEdit.cy.js
index 377882140..edd2b4d53 100644
--- a/tests/Frontend/e2e/AdminServerPoolsEdit.cy.js
+++ b/tests/Frontend/e2e/AdminServerPoolsEdit.cy.js
@@ -610,7 +610,9 @@ describe("Admin server pools edit", function () {
     cy.intercept("PUT", "api/v1/serverPools/1", {
       statusCode: 404,
       body: {
-        message: "No query results for model",
+        message: "model_not_found",
+        model: "server_pool",
+        ids: [1],
       },
     }).as("saveChangesRequest");
 
@@ -625,8 +627,8 @@ describe("Admin server pools edit", function () {
     cy.wait("@serverPoolsRequest");
 
     cy.checkToastMessage([
-      'app.flash.server_error.message_{"message":"No query results for model"}',
-      'app.flash.server_error.error_code_{"statusCode":404}',
+      'app.flash.model_not_found.title_{"model":"app.model.server_pool"}',
+      'app.flash.model_not_found.details_{"ids":"1"}',
     ]);
 
     // Reload
@@ -728,7 +730,9 @@ describe("Admin server pools edit", function () {
     cy.intercept("GET", "api/v1/serverPools/1", {
       statusCode: 404,
       body: {
-        message: "No query results for model",
+        message: "model_not_found",
+        model: "server_pool",
+        ids: [1],
       },
     }).as("serverPoolRequest");
 
@@ -743,8 +747,8 @@ describe("Admin server pools edit", function () {
     cy.wait("@serverPoolsRequest");
 
     cy.checkToastMessage([
-      'app.flash.server_error.message_{"message":"No query results for model"}',
-      'app.flash.server_error.error_code_{"statusCode":404}',
+      'app.flash.model_not_found.title_{"model":"app.model.server_pool"}',
+      'app.flash.model_not_found.details_{"ids":"1"}',
     ]);
 
     // Reload page with 401 error
diff --git a/tests/Frontend/e2e/AdminServerPoolsIndexServerPoolActions.cy.js b/tests/Frontend/e2e/AdminServerPoolsIndexServerPoolActions.cy.js
index b55176956..64701b0e0 100644
--- a/tests/Frontend/e2e/AdminServerPoolsIndexServerPoolActions.cy.js
+++ b/tests/Frontend/e2e/AdminServerPoolsIndexServerPoolActions.cy.js
@@ -197,8 +197,61 @@ describe("Admin server pools index server pool actions", function () {
       'app.flash.server_error.error_code_{"statusCode":500}',
     ]);
 
-    // Check with 401 error
+    // Check with 404 error
+    cy.fixture("serverPools.json").then((serverPools) => {
+      serverPools.data = serverPools.data.filter(
+        (serverPool) => serverPool.id !== 1,
+      );
+      serverPools.meta.to = 1;
+      serverPools.meta.total = 1;
+      serverPools.meta.total_no_filter = 1;
+
+      cy.intercept("GET", "api/v1/serverPools*", {
+        statusCode: 200,
+        body: serverPools,
+      }).as("serverPoolsRequest");
+    });
+
     cy.intercept("DELETE", "api/v1/serverPools/1", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "server_pool",
+        ids: [1],
+      },
+    }).as("deleteServerPoolRequest");
+
+    cy.get('[data-test="dialog-continue-button"]').click();
+
+    cy.wait("@deleteServerPoolRequest");
+
+    // Check that server pool list was refreshed
+    cy.wait("@serverPoolsRequest");
+
+    // Check that dialog is closed and error message is shown
+    cy.get('[data-test="server-pools-delete-dialog"]').should("not.exist");
+
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.server_pool"}',
+      'app.flash.model_not_found.details_{"ids":"1"}',
+    ]);
+
+    // Check that server pool is not in list anymore
+    cy.get('[data-test="server-pool-item"]').should("have.length", 1);
+    cy.get('[data-test="server-pool-item"]')
+      .eq(0)
+      .should("include.text", "Production");
+
+    // Reopen dialog for different server pool
+    cy.get('[data-test="server-pool-item"]')
+      .eq(0)
+      .find('[data-test="server-pools-delete-button"]')
+      .click();
+
+    cy.get('[data-test="server-pools-delete-dialog"]').should("be.visible");
+
+    // Check with 401 error
+    cy.intercept("DELETE", "api/v1/serverPools/2", {
       statusCode: 401,
     }).as("deleteServerPoolRequest");
 
diff --git a/tests/Frontend/e2e/AdminServerPoolsView.cy.js b/tests/Frontend/e2e/AdminServerPoolsView.cy.js
index 6fef329d9..f76b8e049 100644
--- a/tests/Frontend/e2e/AdminServerPoolsView.cy.js
+++ b/tests/Frontend/e2e/AdminServerPoolsView.cy.js
@@ -229,7 +229,9 @@ describe("Admin server pools view", function () {
     cy.intercept("GET", "api/v1/serverPools/1", {
       statusCode: 404,
       body: {
-        message: "No query results for model",
+        message: "model_not_found",
+        model: "server_pool",
+        ids: [1],
       },
     }).as("serverPoolRequest");
 
@@ -244,8 +246,8 @@ describe("Admin server pools view", function () {
     cy.wait("@serverPoolsRequest");
 
     cy.checkToastMessage([
-      'app.flash.server_error.message_{"message":"No query results for model"}',
-      'app.flash.server_error.error_code_{"statusCode":404}',
+      'app.flash.model_not_found.title_{"model":"app.model.server_pool"}',
+      'app.flash.model_not_found.details_{"ids":"1"}',
     ]);
 
     // Reload page with 401 error
diff --git a/tests/Frontend/e2e/AdminServerPoolsViewServerPoolActions.cy.js b/tests/Frontend/e2e/AdminServerPoolsViewServerPoolActions.cy.js
index 0f0d98e74..e1820beaa 100644
--- a/tests/Frontend/e2e/AdminServerPoolsViewServerPoolActions.cy.js
+++ b/tests/Frontend/e2e/AdminServerPoolsViewServerPoolActions.cy.js
@@ -162,6 +162,36 @@ describe("Admin server pools view", function () {
       'app.flash.server_error.error_code_{"statusCode":500}',
     ]);
 
+    // Check with 404 error
+    cy.intercept("DELETE", "api/v1/serverPools/1", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "server_pool",
+        ids: [1],
+      },
+    }).as("deleteServerPoolRequest");
+
+    cy.interceptAdminServerPoolsIndexRequests();
+
+    cy.get('[data-test="dialog-continue-button"]').click();
+
+    cy.wait("@deleteServerPoolRequest");
+
+    // Check that redirect worked and error message is shown
+    cy.url().should("include", "/admin/server_pools").and("not.include", "/1");
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.server_pool"}',
+      'app.flash.model_not_found.details_{"ids":"1"}',
+    ]);
+
+    // Reload view and open delete dialog again
+    cy.visit("/admin/server_pools/1");
+    cy.wait("@serverPoolRequest");
+
+    cy.get('[data-test="server-pools-delete-button"]').click();
+    cy.get('[data-test="server-pools-delete-dialog"]').should("be.visible");
+
     // Check with 401 error
     cy.intercept("DELETE", "api/v1/serverPools/1", {
       statusCode: 401,
diff --git a/tests/Frontend/e2e/AdminServersEdit.cy.js b/tests/Frontend/e2e/AdminServersEdit.cy.js
index 3b02ee5b3..6616bfb98 100644
--- a/tests/Frontend/e2e/AdminServersEdit.cy.js
+++ b/tests/Frontend/e2e/AdminServersEdit.cy.js
@@ -622,7 +622,9 @@ describe("Admin servers edit", function () {
     cy.intercept("PUT", "api/v1/servers/1", {
       statusCode: 404,
       body: {
-        message: "No query results for model",
+        message: "model_not_found",
+        model: "server",
+        ids: [1],
       },
     }).as("saveChangesRequest");
 
@@ -637,8 +639,8 @@ describe("Admin servers edit", function () {
     cy.wait("@serversRequest");
 
     cy.checkToastMessage([
-      'app.flash.server_error.message_{"message":"No query results for model"}',
-      'app.flash.server_error.error_code_{"statusCode":404}',
+      'app.flash.model_not_found.title_{"model":"app.model.server"}',
+      'app.flash.model_not_found.details_{"ids":"1"}',
     ]);
 
     // Reload
@@ -809,7 +811,9 @@ describe("Admin servers edit", function () {
     cy.intercept("GET", "api/v1/servers/1", {
       statusCode: 404,
       body: {
-        message: "No query results for model",
+        message: "model_not_found",
+        model: "server",
+        ids: [1],
       },
     }).as("serverRequest");
 
@@ -824,8 +828,8 @@ describe("Admin servers edit", function () {
     cy.wait("@serversRequest");
 
     cy.checkToastMessage([
-      'app.flash.server_error.message_{"message":"No query results for model"}',
-      'app.flash.server_error.error_code_{"statusCode":404}',
+      'app.flash.model_not_found.title_{"model":"app.model.server"}',
+      'app.flash.model_not_found.details_{"ids":"1"}',
     ]);
 
     // Reload page with 401 error
diff --git a/tests/Frontend/e2e/AdminServersIndexServerActions.cy.js b/tests/Frontend/e2e/AdminServersIndexServerActions.cy.js
index 531bd9fc0..94fa573d3 100644
--- a/tests/Frontend/e2e/AdminServersIndexServerActions.cy.js
+++ b/tests/Frontend/e2e/AdminServersIndexServerActions.cy.js
@@ -149,8 +149,57 @@ describe("Admin servers index server actions", function () {
       'app.flash.server_error.error_code_{"statusCode":500}',
     ]);
 
-    // Check with 401 error
+    // Check 404 error
+    cy.fixture("servers.json").then((servers) => {
+      servers.data = servers.data.filter((server) => server.id !== 3);
+      servers.meta.to = 3;
+      servers.meta.total = 3;
+      servers.meta.total_no_filter = 3;
+
+      servers.data[2].status = -1;
+
+      cy.intercept("GET", "api/v1/servers*", {
+        statusCode: 200,
+        body: servers,
+      }).as("serversRequest");
+    });
+
     cy.intercept("DELETE", "api/v1/servers/3", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "server",
+        ids: [3],
+      },
+    }).as("deleteServerRequest");
+
+    cy.get('[data-test="dialog-continue-button"]').click();
+
+    cy.wait("@deleteServerRequest");
+
+    // Check that server list was refreshed
+    cy.wait("@serversRequest");
+
+    // Check that dialog is closed and error message is shown
+    cy.get('[data-test="servers-delete-dialog"]').should("not.exist");
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.server"}',
+      'app.flash.model_not_found.details_{"ids":"3"}',
+    ]);
+
+    // Check that server is not in list anymore
+    cy.get('[data-test="server-item"]').should("have.length", 3);
+
+    // Reopen dialog for different server
+    cy.get('[data-test="server-item"]')
+      .eq(2)
+      .find('[data-test="servers-delete-button"]')
+      .click();
+
+    cy.get('[data-test="servers-delete-dialog"]').should("be.visible");
+
+    // Check with 401 error
+    cy.intercept("DELETE", "api/v1/servers/4", {
       statusCode: 401,
     }).as("deleteServerRequest");
 
diff --git a/tests/Frontend/e2e/AdminServersView.cy.js b/tests/Frontend/e2e/AdminServersView.cy.js
index ffd6144e3..0d055c16f 100644
--- a/tests/Frontend/e2e/AdminServersView.cy.js
+++ b/tests/Frontend/e2e/AdminServersView.cy.js
@@ -577,7 +577,9 @@ describe("Admin servers view", function () {
     cy.intercept("GET", "api/v1/servers/1", {
       statusCode: 404,
       body: {
-        message: "No query results for model",
+        message: "model_not_found",
+        model: "server",
+        ids: [1],
       },
     }).as("serverRequest");
 
@@ -592,10 +594,9 @@ describe("Admin servers view", function () {
     cy.wait("@serversRequest");
 
     cy.checkToastMessage([
-      'app.flash.server_error.message_{"message":"No query results for model"}',
-      'app.flash.server_error.error_code_{"statusCode":404}',
+      'app.flash.model_not_found.title_{"model":"app.model.server"}',
+      'app.flash.model_not_found.details_{"ids":"1"}',
     ]);
-
     // Reload page with 401 error
     cy.intercept("GET", "api/v1/servers/1", {
       statusCode: 401,
diff --git a/tests/Frontend/e2e/AdminServersViewServerActions.cy.js b/tests/Frontend/e2e/AdminServersViewServerActions.cy.js
index 024f069f4..9d3034331 100644
--- a/tests/Frontend/e2e/AdminServersViewServerActions.cy.js
+++ b/tests/Frontend/e2e/AdminServersViewServerActions.cy.js
@@ -135,6 +135,38 @@ describe("Admin servers view server actions", function () {
       'app.flash.server_error.error_code_{"statusCode":500}',
     ]);
 
+    // Check with 404 error
+    cy.intercept("DELETE", "api/v1/servers/1", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "server",
+        ids: [1],
+      },
+    }).as("deleteServerRequest");
+
+    cy.interceptAdminServersIndexRequests();
+
+    cy.get('[data-test="dialog-continue-button"]').click();
+
+    cy.wait("@deleteServerRequest");
+
+    // Check that redirect worked and error message is shown
+    cy.url().should("include", "/admin/servers").and("not.include", "/1");
+
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.server"}',
+      'app.flash.model_not_found.details_{"ids":"1"}',
+    ]);
+
+    // Reload view and open delete dialog again
+    cy.visit("/admin/servers/1");
+
+    cy.wait("@serverRequest");
+
+    cy.get('[data-test="servers-delete-button"]').click();
+    cy.get('[data-test="servers-delete-dialog"]').should("be.visible");
+
     // Check with 401 error
     cy.intercept("DELETE", "api/v1/servers/1", {
       statusCode: 401,
@@ -421,6 +453,34 @@ describe("Admin servers view server actions", function () {
     cy.url().should("include", "/login?redirect=/admin/servers/1");
 
     cy.checkToastMessage("app.flash.unauthenticated");
+
+    // Check with 404 error
+    cy.interceptAdminServersIndexRequests();
+
+    cy.intercept("POST", "api/v1/servers/1/panic", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "server",
+        ids: [1],
+      },
+    }).as("panicRequest");
+
+    cy.visit("/admin/servers/1");
+
+    cy.wait("@serverRequest");
+
+    cy.get('[data-test="servers-panic-button"]').click();
+
+    cy.wait("@panicRequest");
+
+    // Check that redirect worked and error message is shown
+    cy.url().should("include", "/admin/servers").and("not.include", "/1");
+
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.server"}',
+      'app.flash.model_not_found.details_{"ids":"1"}',
+    ]);
   });
 
   it("switch between edit and view", function () {
diff --git a/tests/Frontend/e2e/AdminUsersEdit.cy.js b/tests/Frontend/e2e/AdminUsersEdit.cy.js
index b49417d8c..1f6c96cbb 100644
--- a/tests/Frontend/e2e/AdminUsersEdit.cy.js
+++ b/tests/Frontend/e2e/AdminUsersEdit.cy.js
@@ -272,7 +272,9 @@ describe("Admin users edit", function () {
     cy.intercept("GET", "api/v1/users/2", {
       statusCode: 404,
       body: {
-        message: "No query results for model",
+        message: "model_not_found",
+        model: "user",
+        ids: [2],
       },
     }).as("userRequest");
 
@@ -288,8 +290,8 @@ describe("Admin users edit", function () {
 
     // Check that error message gets shown
     cy.checkToastMessage([
-      'app.flash.server_error.message_{"message":"No query results for model"}',
-      'app.flash.server_error.error_code_{"statusCode":404}',
+      'app.flash.model_not_found.title_{"model":"app.model.user"}',
+      'app.flash.model_not_found.details_{"ids":"2"}',
     ]);
 
     // Reload page with 401 error
diff --git a/tests/Frontend/e2e/AdminUsersEditBase.cy.js b/tests/Frontend/e2e/AdminUsersEditBase.cy.js
index b18e34af1..e5729604d 100644
--- a/tests/Frontend/e2e/AdminUsersEditBase.cy.js
+++ b/tests/Frontend/e2e/AdminUsersEditBase.cy.js
@@ -701,7 +701,9 @@ describe("Admin users edit base", function () {
     cy.intercept("POST", "api/v1/users/2", {
       statusCode: 404,
       body: {
-        message: "No query results for model",
+        message: "model_not_found",
+        model: "user",
+        ids: [2],
       },
     }).as("saveChangesRequest");
 
@@ -716,8 +718,8 @@ describe("Admin users edit base", function () {
     cy.wait("@usersRequest");
 
     cy.checkToastMessage([
-      'app.flash.server_error.message_{"message":"No query results for model"}',
-      'app.flash.server_error.error_code_{"statusCode":404}',
+      'app.flash.model_not_found.title_{"model":"app.model.user"}',
+      'app.flash.model_not_found.details_{"ids":"2"}',
     ]);
 
     // Visit edit page again
diff --git a/tests/Frontend/e2e/AdminUsersEditEmail.cy.js b/tests/Frontend/e2e/AdminUsersEditEmail.cy.js
index 927fdc84c..80c6960a8 100644
--- a/tests/Frontend/e2e/AdminUsersEditEmail.cy.js
+++ b/tests/Frontend/e2e/AdminUsersEditEmail.cy.js
@@ -155,7 +155,9 @@ describe("Admin users edit email", function () {
     cy.intercept("PUT", "api/v1/users/2/email", {
       statusCode: 404,
       body: {
-        message: "No query results for model",
+        message: "model_not_found",
+        model: "user",
+        ids: [2],
       },
     }).as("saveChangesRequest");
 
@@ -170,8 +172,8 @@ describe("Admin users edit email", function () {
     cy.wait("@usersRequest");
 
     cy.checkToastMessage([
-      'app.flash.server_error.message_{"message":"No query results for model"}',
-      'app.flash.server_error.error_code_{"statusCode":404}',
+      'app.flash.model_not_found.title_{"model":"app.model.user"}',
+      'app.flash.model_not_found.details_{"ids":"2"}',
     ]);
 
     // Visit edit page again
diff --git a/tests/Frontend/e2e/AdminUsersEditOthers.cy.js b/tests/Frontend/e2e/AdminUsersEditOthers.cy.js
index ea55d4af6..4a312c239 100644
--- a/tests/Frontend/e2e/AdminUsersEditOthers.cy.js
+++ b/tests/Frontend/e2e/AdminUsersEditOthers.cy.js
@@ -187,7 +187,9 @@ describe("Admin users edit others", function () {
     cy.intercept("POST", "api/v1/users/2", {
       statusCode: 404,
       body: {
-        message: "No query results for model",
+        message: "model_not_found",
+        model: "user",
+        ids: [2],
       },
     }).as("saveChangesRequest");
 
@@ -200,8 +202,8 @@ describe("Admin users edit others", function () {
     cy.wait("@usersRequest");
 
     cy.checkToastMessage([
-      'app.flash.server_error.message_{"message":"No query results for model"}',
-      'app.flash.server_error.error_code_{"statusCode":404}',
+      'app.flash.model_not_found.title_{"model":"app.model.user"}',
+      'app.flash.model_not_found.details_{"ids":"2"}',
     ]);
 
     // Visit edit page again
diff --git a/tests/Frontend/e2e/AdminUsersEditSecurity.cy.js b/tests/Frontend/e2e/AdminUsersEditSecurity.cy.js
index 3b0f2d9bf..d481139d4 100644
--- a/tests/Frontend/e2e/AdminUsersEditSecurity.cy.js
+++ b/tests/Frontend/e2e/AdminUsersEditSecurity.cy.js
@@ -563,7 +563,9 @@ describe("Admin users edit email", function () {
     cy.intercept("PUT", "api/v1/users/2 ", {
       statusCode: 404,
       body: {
-        message: "No query results for model",
+        message: "model_not_found",
+        model: "user",
+        ids: [2],
       },
     }).as("saveChangesRequest");
 
@@ -578,8 +580,8 @@ describe("Admin users edit email", function () {
     cy.wait("@usersRequest");
 
     cy.checkToastMessage([
-      'app.flash.server_error.message_{"message":"No query results for model"}',
-      'app.flash.server_error.error_code_{"statusCode":404}',
+      'app.flash.model_not_found.title_{"model":"app.model.user"}',
+      'app.flash.model_not_found.details_{"ids":"2"}',
     ]);
 
     // Visit edit page again
@@ -742,7 +744,9 @@ describe("Admin users edit email", function () {
     cy.intercept("PUT", "api/v1/users/2/password", {
       statusCode: 404,
       body: {
-        message: "No query results for model",
+        message: "model_not_found",
+        model: "user",
+        ids: [2],
       },
     }).as("saveChangesRequest");
 
@@ -757,8 +761,8 @@ describe("Admin users edit email", function () {
     cy.wait("@usersRequest");
 
     cy.checkToastMessage([
-      'app.flash.server_error.message_{"message":"No query results for model"}',
-      'app.flash.server_error.error_code_{"statusCode":404}',
+      'app.flash.model_not_found.title_{"model":"app.model.user"}',
+      'app.flash.model_not_found.details_{"ids":"2"}',
     ]);
 
     // Visit edit page again
diff --git a/tests/Frontend/e2e/AdminUsersIndexUserActions.cy.js b/tests/Frontend/e2e/AdminUsersIndexUserActions.cy.js
index 278a9b46b..ba1550364 100644
--- a/tests/Frontend/e2e/AdminUsersIndexUserActions.cy.js
+++ b/tests/Frontend/e2e/AdminUsersIndexUserActions.cy.js
@@ -153,8 +153,56 @@ describe("Admin users index user actions", function () {
       'app.flash.server_error.error_code_{"statusCode":500}',
     ]);
 
-    // Check with 401 error
+    // Check with 404 error
+    cy.fixture("users.json").then((users) => {
+      users.data = users.data.filter((user) => user.id !== 3);
+      users.meta.to = 3;
+      users.meta.total = 3;
+      users.meta.total_no_filter = 3;
+
+      cy.intercept("GET", "api/v1/users*", {
+        statusCode: 200,
+        body: users,
+      }).as("usersRequest");
+    });
+
     cy.intercept("DELETE", "api/v1/users/3", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "user",
+        ids: [3],
+      },
+    }).as("deleteUserRequest");
+
+    cy.get('[data-test="dialog-continue-button"]').click();
+
+    cy.wait("@deleteUserRequest");
+
+    // Check that user list was refreshed
+    cy.wait("@usersRequest");
+
+    // Check that dialog is closed and error message is shown
+    cy.get('[data-test="users-delete-dialog"]').should("not.exist");
+
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.user"}',
+      'app.flash.model_not_found.details_{"ids":"3"}',
+    ]);
+
+    // Check that user is not in list anymore
+    cy.get('[data-test="user-item"]').should("have.length", 3);
+
+    // Reopen dialog for different user
+    cy.get('[data-test="user-item"]')
+      .eq(1)
+      .find('[data-test="users-delete-button"]')
+      .click();
+
+    cy.get('[data-test="users-delete-dialog"]').should("be.visible");
+
+    // Check with 401 error
+    cy.intercept("DELETE", "api/v1/users/2", {
       statusCode: 401,
     }).as("deleteUserRequest");
 
diff --git a/tests/Frontend/e2e/AdminUsersView.cy.js b/tests/Frontend/e2e/AdminUsersView.cy.js
index 8c9d4f792..0bb703321 100644
--- a/tests/Frontend/e2e/AdminUsersView.cy.js
+++ b/tests/Frontend/e2e/AdminUsersView.cy.js
@@ -556,7 +556,9 @@ describe("Admin users view", function () {
     cy.intercept("GET", "api/v1/users/2", {
       statusCode: 404,
       body: {
-        message: "No query results for model",
+        message: "model_not_found",
+        model: "user",
+        ids: [2],
       },
     }).as("userRequest");
 
@@ -572,8 +574,8 @@ describe("Admin users view", function () {
 
     // Check that error message gets shown
     cy.checkToastMessage([
-      'app.flash.server_error.message_{"message":"No query results for model"}',
-      'app.flash.server_error.error_code_{"statusCode":404}',
+      'app.flash.model_not_found.title_{"model":"app.model.user"}',
+      'app.flash.model_not_found.details_{"ids":"2"}',
     ]);
 
     // Reload page with 401 error
diff --git a/tests/Frontend/e2e/AdminUsersViewUserActions.cy.js b/tests/Frontend/e2e/AdminUsersViewUserActions.cy.js
index 3c8057ff7..dbec5df87 100644
--- a/tests/Frontend/e2e/AdminUsersViewUserActions.cy.js
+++ b/tests/Frontend/e2e/AdminUsersViewUserActions.cy.js
@@ -127,6 +127,38 @@ describe("Admin users view user actions", function () {
       'app.flash.server_error.error_code_{"statusCode":500}',
     ]);
 
+    // Check with 404 error
+    cy.intercept("DELETE", "api/v1/users/2", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "user",
+        ids: [2],
+      },
+    }).as("deleteUserRequest");
+
+    cy.interceptAdminUsersIndexRequests();
+
+    cy.get('[data-test="dialog-continue-button"]').click();
+
+    cy.wait("@deleteUserRequest");
+
+    // Check that redirect worked and error message is shown
+    cy.url().should("include", "/admin/users").and("not.include", "/2");
+
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.user"}',
+      'app.flash.model_not_found.details_{"ids":"2"}',
+    ]);
+
+    // Reload view and open delete dialog again
+    cy.visit("/admin/users/2");
+
+    cy.wait("@userRequest");
+
+    cy.get('[data-test="users-delete-button"]').click();
+    cy.get('[data-test="users-delete-dialog"]').should("be.visible");
+
     // Check with 401 error
     cy.intercept("DELETE", "api/v1/users/2", {
       statusCode: 401,
@@ -223,6 +255,38 @@ describe("Admin users view user actions", function () {
       'app.flash.server_error.error_code_{"statusCode":500}',
     ]);
 
+    // Check with 404 error
+    cy.intercept("POST", "api/v1/users/2/resetPassword", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "user",
+        ids: [2],
+      },
+    }).as("resetPasswordRequest");
+
+    cy.interceptAdminUsersIndexRequests();
+
+    cy.get('[data-test="dialog-continue-button"]').click();
+
+    cy.wait("@resetPasswordRequest");
+
+    // Check that redirect worked and error message is shown
+    cy.url().should("include", "/admin/users").and("not.include", "/2");
+
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.user"}',
+      'app.flash.model_not_found.details_{"ids":"2"}',
+    ]);
+
+    // Reload view and open reset password dialog again
+    cy.visit("/admin/users/2");
+
+    cy.wait("@userRequest");
+
+    cy.get('[data-test="users-reset-password-button"]').click();
+    cy.get('[data-test="users-reset-password-dialog"]').should("be.visible");
+
     // Check with 401 error
     cy.intercept("POST", "api/v1/users/2/resetPassword", {
       statusCode: 401,
diff --git a/tests/Frontend/e2e/RoomsIndex.cy.js b/tests/Frontend/e2e/RoomsIndex.cy.js
index 3cd1d5504..38f049d7e 100644
--- a/tests/Frontend/e2e/RoomsIndex.cy.js
+++ b/tests/Frontend/e2e/RoomsIndex.cy.js
@@ -1934,7 +1934,7 @@ describe("Room Index", function () {
     });
   });
 
-  it("trigger favorites button errors", function () {
+  it("trigger favorites button errors (room card)", function () {
     cy.fixture("rooms.json").then((rooms) => {
       rooms.data = rooms.data.slice(0, 1);
       rooms.meta.last_page = 3;
@@ -1997,6 +1997,269 @@ describe("Room Index", function () {
 
     cy.checkToastMessage("app.flash.unauthenticated");
 
+    // Test add to favorites with 404 error
+    cy.visit("/rooms");
+
+    cy.wait("@roomRequest");
+
+    cy.intercept("POST", "api/v1/rooms/abc-def-123/favorites", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "room",
+        ids: ["abc-def-123"],
+      },
+    }).as("addFavoritesRequest");
+
+    cy.get('[data-test="room-card"]')
+      .eq(0)
+      .within(() => {
+        cy.get('[data-test="room-favorites-button"]')
+          .should("have.attr", "aria-label", "rooms.favorites.add")
+          .click();
+      });
+
+    cy.wait("@addFavoritesRequest");
+
+    // Check that rooms are reloaded and error message is shown
+    cy.wait("@roomRequest").then((interception) => {
+      expect(interception.request.query).to.contain({
+        page: "1",
+      });
+    });
+
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
+
+    // Visit rooms again with a room that is already a favorite
+    cy.fixture("rooms.json").then((rooms) => {
+      rooms.data = rooms.data.slice(0, 1);
+      rooms.data[0].is_favorite = true;
+
+      rooms.meta.last_page = 3;
+      rooms.meta.per_page = 1;
+      rooms.meta.to = 1;
+
+      cy.intercept("GET", "api/v1/rooms?*", {
+        statusCode: 200,
+        body: rooms,
+      }).as("roomRequest");
+    });
+
+    cy.visit("/rooms");
+
+    cy.wait("@roomRequest");
+
+    // Test remove from favorites with general error
+    cy.intercept("DELETE", "api/v1/rooms/abc-def-123/favorites", {
+      statusCode: 500,
+      body: {
+        message: "Test remove favorite error",
+      },
+    }).as("deleteFavoritesRequest");
+
+    cy.get('[data-test="room-card"]')
+      .eq(0)
+      .within(() => {
+        cy.get('[data-test="room-favorites-button"]')
+          .should("have.attr", "aria-label", "rooms.favorites.remove")
+          .click();
+
+        cy.wait("@deleteFavoritesRequest");
+        cy.wait("@roomRequest");
+      });
+
+    // Check that error message is shown and button stayed the same
+    cy.checkToastMessage([
+      'app.flash.server_error.message_{"message":"Test remove favorite error"}',
+      'app.flash.server_error.error_code_{"statusCode":500}',
+    ]);
+
+    // Test remove from favorites with unauthenticated error
+    cy.intercept("DELETE", "api/v1/rooms/abc-def-123/favorites", {
+      statusCode: 401,
+    }).as("addFavoritesRequest");
+
+    cy.get('[data-test="room-card"]')
+      .eq(0)
+      .within(() => {
+        cy.get('[data-test="room-favorites-button"]')
+          .should("have.attr", "aria-label", "rooms.favorites.remove")
+          .click();
+
+        cy.wait("@addFavoritesRequest");
+        cy.wait("@roomRequest");
+      });
+
+    // Check that redirect worked and error message is shown
+    cy.url().should("include", "/login?redirect=/rooms");
+
+    cy.checkToastMessage("app.flash.unauthenticated");
+
+    // Test remove from favorites with 404 error
+    cy.visit("/rooms");
+
+    cy.wait("@roomRequest");
+
+    cy.intercept("DELETE", "api/v1/rooms/abc-def-123/favorites", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "room",
+        ids: ["abc-def-123"],
+      },
+    }).as("deleteFavoritesRequest");
+
+    cy.get('[data-test="room-card"]')
+      .eq(0)
+      .within(() => {
+        cy.get('[data-test="room-favorites-button"]')
+          .should("have.attr", "aria-label", "rooms.favorites.remove")
+          .click();
+      });
+
+    cy.wait("@deleteFavoritesRequest");
+
+    // Check that rooms are reloaded and error message is shown
+    cy.wait("@roomRequest").then((interception) => {
+      expect(interception.request.query).to.contain({
+        page: "1",
+      });
+    });
+
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
+  });
+
+  it("trigger favorites button errors (room info dialog)", function () {
+    cy.fixture("rooms.json").then((rooms) => {
+      rooms.data = rooms.data.slice(0, 1);
+      rooms.meta.last_page = 3;
+      rooms.meta.per_page = 1;
+      rooms.meta.to = 1;
+
+      rooms.data[0].short_description = "Room short descriptions";
+
+      cy.intercept("GET", "api/v1/rooms?*", {
+        statusCode: 200,
+        body: rooms,
+      }).as("roomRequest");
+    });
+
+    cy.visit("/rooms");
+
+    cy.wait("@roomRequest");
+
+    // Test add to favorites with general error
+    cy.intercept("POST", "api/v1/rooms/abc-def-123/favorites", {
+      statusCode: 500,
+      body: {
+        message: "Test add favorite error",
+      },
+    }).as("addFavoritesRequest");
+
+    cy.get('[data-test="room-info-dialog"]').should("not.exist");
+
+    cy.get('[data-test="room-card"]')
+      .eq(0)
+      .within(() => {
+        cy.get('[data-test="room-info-button"]').click();
+      });
+
+    cy.get('[data-test="room-info-dialog"]')
+      .should("be.visible")
+      .within(() => {
+        cy.get('[data-test="room-favorites-button"]')
+          .should("have.attr", "aria-label", "rooms.favorites.add")
+          .click();
+
+        cy.wait("@addFavoritesRequest");
+        cy.wait("@roomRequest");
+      });
+
+    // Check that error message is shown and button stayed the same
+    cy.checkToastMessage([
+      'app.flash.server_error.message_{"message":"Test add favorite error"}',
+      'app.flash.server_error.error_code_{"statusCode":500}',
+    ]);
+
+    // Test add to favorites with unauthenticated error
+    cy.intercept("POST", "api/v1/rooms/abc-def-123/favorites", {
+      statusCode: 401,
+    }).as("addFavoritesRequest");
+
+    cy.get('[data-test="room-info-dialog"]').should("not.exist");
+
+    cy.get('[data-test="room-card"]')
+      .eq(0)
+      .within(() => {
+        cy.get('[data-test="room-info-button"]').click();
+      });
+
+    cy.get('[data-test="room-info-dialog"]')
+      .should("be.visible")
+      .within(() => {
+        cy.get('[data-test="room-favorites-button"]')
+          .should("have.attr", "aria-label", "rooms.favorites.add")
+          .click();
+
+        cy.wait("@addFavoritesRequest");
+        cy.wait("@roomRequest");
+      });
+
+    // Check that redirect worked and error message is shown
+    cy.url().should("include", "/login?redirect=/rooms");
+
+    cy.checkToastMessage("app.flash.unauthenticated");
+
+    // Test add to favorites with 404 error
+    cy.visit("/rooms");
+
+    cy.wait("@roomRequest");
+
+    cy.intercept("POST", "api/v1/rooms/abc-def-123/favorites", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "room",
+        ids: ["abc-def-123"],
+      },
+    }).as("addFavoritesRequest");
+
+    cy.get('[data-test="room-info-dialog"]').should("not.exist");
+
+    cy.get('[data-test="room-card"]')
+      .eq(0)
+      .within(() => {
+        cy.get('[data-test="room-info-button"]').click();
+      });
+
+    cy.get('[data-test="room-info-dialog"]')
+      .should("be.visible")
+      .within(() => {
+        cy.get('[data-test="room-favorites-button"]')
+          .should("have.attr", "aria-label", "rooms.favorites.add")
+          .click();
+      });
+
+    cy.wait("@addFavoritesRequest");
+
+    // Check that rooms are reloaded and error message is shown
+    cy.wait("@roomRequest").then((interception) => {
+      expect(interception.request.query).to.contain({
+        page: "1",
+      });
+    });
+
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
+
     // Visit rooms again with a room that is already a favorite
     cy.fixture("rooms.json").then((rooms) => {
       rooms.data = rooms.data.slice(0, 1);
@@ -2024,8 +2287,16 @@ describe("Room Index", function () {
       },
     }).as("deleteFavoritesRequest");
 
+    cy.get('[data-test="room-info-dialog"]').should("not.exist");
+
     cy.get('[data-test="room-card"]')
       .eq(0)
+      .within(() => {
+        cy.get('[data-test="room-info-button"]').click();
+      });
+
+    cy.get('[data-test="room-info-dialog"]')
+      .should("be.visible")
       .within(() => {
         cy.get('[data-test="room-favorites-button"]')
           .should("have.attr", "aria-label", "rooms.favorites.remove")
@@ -2046,8 +2317,16 @@ describe("Room Index", function () {
       statusCode: 401,
     }).as("addFavoritesRequest");
 
+    cy.get('[data-test="room-info-dialog"]').should("not.exist");
+
     cy.get('[data-test="room-card"]')
       .eq(0)
+      .within(() => {
+        cy.get('[data-test="room-info-button"]').click();
+      });
+
+    cy.get('[data-test="room-info-dialog"]')
+      .should("be.visible")
       .within(() => {
         cy.get('[data-test="room-favorites-button"]')
           .should("have.attr", "aria-label", "rooms.favorites.remove")
@@ -2061,6 +2340,50 @@ describe("Room Index", function () {
     cy.url().should("include", "/login?redirect=/rooms");
 
     cy.checkToastMessage("app.flash.unauthenticated");
+
+    // Test remove from favorites with 404 error
+    cy.visit("/rooms");
+
+    cy.wait("@roomRequest");
+
+    cy.intercept("DELETE", "api/v1/rooms/abc-def-123/favorites", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "room",
+        ids: ["abc-def-123"],
+      },
+    }).as("deleteFavoritesRequest");
+
+    cy.get('[data-test="room-info-dialog"]').should("not.exist");
+
+    cy.get('[data-test="room-card"]')
+      .eq(0)
+      .within(() => {
+        cy.get('[data-test="room-info-button"]').click();
+      });
+
+    cy.get('[data-test="room-info-dialog"]')
+      .should("be.visible")
+      .within(() => {
+        cy.get('[data-test="room-favorites-button"]')
+          .should("have.attr", "aria-label", "rooms.favorites.remove")
+          .click();
+      });
+
+    cy.wait("@deleteFavoritesRequest");
+
+    // Check that rooms are reloaded and error message is shown
+    cy.wait("@roomRequest").then((interception) => {
+      expect(interception.request.query).to.contain({
+        page: "1",
+      });
+    });
+
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
   });
 
   it("error loading rooms", function () {
diff --git a/tests/Frontend/e2e/RoomsViewDescription.cy.js b/tests/Frontend/e2e/RoomsViewDescription.cy.js
index 58076a92c..0c096418c 100644
--- a/tests/Frontend/e2e/RoomsViewDescription.cy.js
+++ b/tests/Frontend/e2e/RoomsViewDescription.cy.js
@@ -462,6 +462,38 @@ describe("Rooms view description", function () {
       "api/v1/rooms/abc-def-123/description",
       "description",
     );
+
+    // Reload page
+    cy.interceptRoomViewRequests();
+    cy.reload();
+
+    // Check with 404 error (room not found)
+    cy.interceptRoomIndexRequests();
+    cy.intercept("PUT", "api/v1/rooms/abc-def-123/description", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "room",
+        ids: ["abc-def-123"],
+      },
+    }).as("saveDescriptionRequest");
+
+    cy.get('[data-test="room-description-edit-button"]').click();
+    cy.get('[data-test="tip-tap-editor"]').should("be.visible");
+    cy.get('[data-test="room-description-save-button"]').click();
+
+    cy.wait("@saveDescriptionRequest");
+
+    // Check that redirect to room index page worked
+    cy.url()
+      .should("include", "/rooms")
+      .and("not.include", "/rooms/abc-def-123");
+
+    // Check that error message gets shown
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
   });
 
   it("description changes", function () {
diff --git a/tests/Frontend/e2e/RoomsViewFiles.cy.js b/tests/Frontend/e2e/RoomsViewFiles.cy.js
index c4133b1f5..e4dc9f376 100644
--- a/tests/Frontend/e2e/RoomsViewFiles.cy.js
+++ b/tests/Frontend/e2e/RoomsViewFiles.cy.js
@@ -719,6 +719,56 @@ describe("Rooms View Files", function () {
     cy.get('[data-test="paginator-page"]')
       .eq(0)
       .should("have.attr", "data-p-active", "true");
+
+    // Check with 404 error (room not found) as authenticated user
+    cy.interceptRoomIndexRequests();
+
+    cy.intercept("GET", "api/v1/rooms/abc-def-123/files*", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "room",
+        ids: ["abc-def-123"],
+      },
+    }).as("roomFilesRequest");
+
+    cy.reload();
+    cy.wait("@roomFilesRequest");
+
+    // Check that redirect to room index page worked
+    cy.url()
+      .should("include", "/rooms")
+      .and("not.include", "/rooms/abc-def-123");
+
+    // Check that error message gets shown
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
+
+    // Check with 404 error (room not found) as guest
+    cy.intercept("GET", "api/v1/currentUser", { data: [] });
+    cy.fixture("room.json").then((room) => {
+      room.data.current_user = null;
+
+      cy.intercept("GET", "api/v1/rooms/abc-def-123*", {
+        statusCode: 200,
+        body: room,
+      }).as("roomRequest");
+    });
+
+    cy.visit("/rooms/abc-def-123#tab=files");
+
+    cy.wait("@roomFilesRequest");
+
+    // Check that redirect to 404 page worked
+    cy.url().should("include", "/404").and("not.include", "/rooms/abc-def-123");
+
+    // Check that error message gets shown
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
   });
 
   it("load files page out of range", function () {
diff --git a/tests/Frontend/e2e/RoomsViewFilesFileActions.cy.js b/tests/Frontend/e2e/RoomsViewFilesFileActions.cy.js
index 9275dbc52..1b2473bf3 100644
--- a/tests/Frontend/e2e/RoomsViewFilesFileActions.cy.js
+++ b/tests/Frontend/e2e/RoomsViewFilesFileActions.cy.js
@@ -332,6 +332,42 @@ describe("Rooms view files file actions", function () {
       "/api/v1/rooms/abc-def-123/files",
       "files",
     );
+
+    // Reload page
+    cy.interceptRoomViewRequests();
+    cy.interceptRoomFilesRequest(true);
+    cy.reload();
+
+    // Check 404 error (room not found)
+    cy.interceptRoomIndexRequests();
+
+    cy.intercept("POST", "/api/v1/rooms/abc-def-123/files", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "room",
+        ids: ["abc-def-123"],
+      },
+    }).as("uploadFileRequest");
+
+    cy.get('[data-test="room-files-upload-button"]').click();
+    cy.get('[data-test="room-files-upload-dialog"]')
+      .should("be.visible")
+      .find("#file")
+      .selectFile("tests/Frontend/fixtures/files/testFile.txt", {
+        force: true,
+      });
+
+    cy.wait("@uploadFileRequest");
+
+    // Check that redirect to room index page worked
+    cy.url().should("include", "/rooms").and("not.include", "abc-def-123");
+
+    // Check that error message is shown
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
   });
 
   it("delete file", function () {
@@ -417,7 +453,9 @@ describe("Rooms view files file actions", function () {
     cy.intercept("DELETE", "/api/v1/rooms/abc-def-123/files/3", {
       statusCode: 404,
       body: {
-        message: "No query results for model",
+        message: "model_not_found",
+        model: "room_file",
+        ids: [3],
       },
     }).as("deleteFileRequest");
 
@@ -504,6 +542,44 @@ describe("Rooms view files file actions", function () {
       "/api/v1/rooms/abc-def-123/files/1",
       "files",
     );
+
+    // Reload page
+    cy.interceptRoomViewRequests();
+    cy.interceptRoomFilesRequest(true);
+    cy.reload();
+
+    // Check with 404 error (room not found)
+    cy.interceptRoomIndexRequests();
+
+    cy.intercept("DELETE", "/api/v1/rooms/abc-def-123/files/1", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "room",
+        ids: ["abc-def-123"],
+      },
+    }).as("deleteFileRequest");
+
+    cy.get('[data-test="room-file-item"]')
+      .eq(0)
+      .find('[data-test="room-files-delete-button"]')
+      .click();
+
+    cy.get('[data-test="room-files-delete-dialog"]')
+      .should("be.visible")
+      .find('[data-test="dialog-continue-button"]')
+      .click();
+
+    cy.wait("@deleteFileRequest");
+
+    // Check that redirect to room index page worked
+    cy.url().should("include", "/rooms").and("not.include", "abc-def-123");
+
+    // Check that error message is shown
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
   });
 
   it("change file settings", function () {
@@ -613,7 +689,9 @@ describe("Rooms view files file actions", function () {
     cy.intercept("PUT", "/api/v1/rooms/abc-def-123/files/3", {
       statusCode: 404,
       body: {
-        message: "No query results for model",
+        message: "model_not_found",
+        model: "room_file",
+        ids: [3],
       },
     }).as("editFileRequest");
 
@@ -724,6 +802,44 @@ describe("Rooms view files file actions", function () {
       "/api/v1/rooms/abc-def-123/files/1",
       "files",
     );
+
+    // Reload page
+    cy.interceptRoomViewRequests();
+    cy.interceptRoomFilesRequest(true);
+    cy.reload();
+
+    // Check with 404 error (room not found)
+    cy.interceptRoomIndexRequests();
+
+    cy.intercept("PUT", "/api/v1/rooms/abc-def-123/files/1", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "room",
+        ids: ["abc-def-123"],
+      },
+    }).as("editFileRequest");
+
+    cy.get('[data-test="room-file-item"]')
+      .eq(0)
+      .find('[data-test="room-files-edit-button"]')
+      .click();
+
+    cy.get('[data-test="room-files-edit-dialog"]')
+      .should("be.visible")
+      .find('[data-test="dialog-save-button"]')
+      .click();
+
+    cy.wait("@editFileRequest");
+
+    // Check that redirect to room index page worked
+    cy.url().should("include", "/rooms").and("not.include", "abc-def-123");
+
+    // Check that error message is shown
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
   });
 
   it("download file with terms of use", function () {
diff --git a/tests/Frontend/e2e/RoomsViewGeneral.cy.js b/tests/Frontend/e2e/RoomsViewGeneral.cy.js
index 943ff144c..a42c3f018 100644
--- a/tests/Frontend/e2e/RoomsViewGeneral.cy.js
+++ b/tests/Frontend/e2e/RoomsViewGeneral.cy.js
@@ -693,6 +693,65 @@ describe("Room View general", function () {
 
     // Check that access code overlay is hidden
     cy.get('[data-test="room-access-code-overlay"]').should("not.exist");
+
+    // Check with 404 error (room not found) as authenticated user
+    cy.interceptRoomIndexRequests();
+    cy.intercept("POST", "api/v1/rooms/abc-def-123/auth", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "room",
+        ids: ["abc-def-123"],
+      },
+    }).as("roomAuthRequest");
+
+    cy.reload();
+
+    cy.wait("@roomRequest");
+
+    cy.get('[data-test="room-login-button"]').click();
+
+    cy.wait("@roomAuthRequest");
+
+    // Check that redirect to room index page worked
+    cy.url()
+      .should("include", "/rooms")
+      .and("not.include", "/rooms/abc-def-123");
+
+    // Check that error message is shown
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
+
+    // Check with 404 error (room not found) as guest
+    cy.intercept("GET", "api/v1/currentUser", {});
+    cy.fixture("room.json").then((room) => {
+      room.data.current_user = null;
+      room.data.authenticated = false;
+
+      cy.intercept("GET", "api/v1/rooms/abc-def-123*", {
+        statusCode: 200,
+        body: room,
+      }).as("roomRequest");
+    });
+
+    cy.visit("/rooms/abc-def-123");
+
+    cy.wait("@roomRequest");
+
+    cy.get('[data-test="room-login-button"]').click();
+
+    cy.wait("@roomAuthRequest");
+
+    // Check that redirect to 404 page worked
+    cy.url().should("include", "/404").and("not.include", "/rooms/abc-def-123");
+
+    // Check that error message is shown
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
   });
 
   it("room view with access code errors", function () {
@@ -1589,6 +1648,37 @@ describe("Room View general", function () {
     cy.contains("rooms.index.room_component.never_started").should(
       "be.visible",
     );
+
+    // Check with 404 error
+    cy.intercept("POST", "api/v1/rooms/abc-def-123/auth", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "room",
+        ids: ["abc-def-123"],
+      },
+    }).as("roomAuthRequest");
+
+    // Visit room with personalized link
+    cy.visit(
+      "/rooms/abc-def-123/xWDCevVTcMys1ftzt3nFPgU56Wf32fopFWgAEBtklSkFU22z1ntA4fBHsHeMygMiOa9szJbNEfBAgEWSLNWg2gcF65PwPZ2ylPQR",
+    );
+
+    cy.wait("@roomAuthRequest").then((interception) => {
+      expect(interception.request.body).to.eql({
+        personalized_link_token:
+          "xWDCevVTcMys1ftzt3nFPgU56Wf32fopFWgAEBtklSkFU22z1ntA4fBHsHeMygMiOa9szJbNEfBAgEWSLNWg2gcF65PwPZ2ylPQR",
+        type: 1,
+      });
+    });
+
+    // Check that redirect to 404 page worked and error message is shown
+    cy.url().should("include", "/404").and("not.include", "rooms/abc-def-123");
+
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
   });
 
   it("room view with personalized link errors", function () {
@@ -2360,6 +2450,51 @@ describe("Room View general", function () {
 
     cy.contains("auth.login").should("be.visible");
 
+    // Visit room page again
+    cy.fixture("room.json").then((room) => {
+      room.data.owner = {
+        id: 2,
+        name: "Max Doe",
+      };
+      room.data.description = "<p>Test</p>";
+      room.data.allow_membership = true;
+
+      cy.intercept("GET", "api/v1/rooms/abc-def-123*", {
+        statusCode: 200,
+        body: room,
+      }).as("roomRequest");
+    });
+
+    cy.visit("/rooms/abc-def-123");
+
+    cy.wait("@roomRequest");
+
+    // Check join membership with 404 error (room not found)
+    cy.interceptRoomIndexRequests();
+
+    cy.intercept("POST", "api/v1/rooms/abc-def-123/membership*", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "room",
+        ids: ["abc-def-123"],
+      },
+    }).as("joinMembershipRequest");
+
+    cy.get('[data-test="room-join-membership-button"]').click();
+
+    cy.wait("@joinMembershipRequest");
+
+    // Check that redirect worked and error message is shown
+    cy.url()
+      .should("include", "/rooms")
+      .and("not.include", "rooms/abc-def-123");
+
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
+
     // Reload room with user being a member of the room
     cy.fixture("room.json").then((room) => {
       room.data.owner = {
@@ -2451,6 +2586,54 @@ describe("Room View general", function () {
 
     // Check that access code overlay is shown
     cy.get('[data-test="room-access-code-overlay"]').should("be.visible");
+
+    // Reload room with user being a member of the room
+    cy.fixture("room.json").then((room) => {
+      room.data.owner = {
+        id: 2,
+        name: "Max Doe",
+      };
+      room.data.description = "<p>Test</p>";
+      room.data.allow_membership = true;
+      room.data.is_member = true;
+
+      cy.intercept("GET", "api/v1/rooms/abc-def-123*", {
+        statusCode: 200,
+        body: room,
+      }).as("roomRequest");
+    });
+
+    cy.visit("/rooms/abc-def-123");
+
+    cy.wait("@roomRequest");
+
+    // Check end membership with 404 error (room not found)
+    cy.intercept("DELETE", "api/v1/rooms/abc-def-123/membership", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "room",
+        ids: ["abc-def-123"],
+      },
+    }).as("endMembershipRequest");
+
+    cy.get('[data-test="room-end-membership-button"]').click();
+
+    cy.get('[data-test="end-membership-dialog"]').should("be.visible");
+    cy.get('[data-test="dialog-continue-button"]').click();
+
+    cy.wait("@endMembershipRequest");
+
+    // Check that redirect worked and error message is shown
+    cy.url()
+      .should("include", "/rooms")
+      .and("not.include", "rooms/abc-def-123");
+
+    // Check that error message is shown
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
   });
 
   it("trigger favorites button", function () {
@@ -2625,6 +2808,51 @@ describe("Room View general", function () {
 
     cy.contains("auth.login").should("be.visible");
 
+    // Visit room page again
+    cy.fixture("room.json").then((room) => {
+      room.data.owner = {
+        id: 2,
+        name: "Max Doe",
+      };
+      room.data.description = "<p>Test</p>";
+      room.data.allow_membership = true;
+
+      cy.intercept("GET", "api/v1/rooms/abc-def-123", {
+        statusCode: 200,
+        body: room,
+      }).as("roomRequest");
+    });
+
+    cy.visit("/rooms/abc-def-123");
+
+    cy.wait("@roomRequest");
+
+    // Test add to favorites with 404 error (room not found)
+    cy.interceptRoomIndexRequests();
+
+    cy.intercept("POST", "api/v1/rooms/abc-def-123/favorites", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "room",
+        ids: ["abc-def-123"],
+      },
+    }).as("addFavoritesRequest");
+
+    cy.get('[data-test="room-favorites-button"]').click();
+
+    cy.wait("@addFavoritesRequest");
+
+    // Check that redirect worked and error message is shown
+    cy.url()
+      .should("include", "/rooms")
+      .and("not.include", "rooms/abc-def-123");
+
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
+
     // Reload room but room is already in favorites
     cy.fixture("room.json").then((room) => {
       room.data.owner = {
@@ -2699,6 +2927,54 @@ describe("Room View general", function () {
 
     // Check that access code overlay is shown
     cy.get('[data-test="room-access-code-overlay"]').should("be.visible");
+
+    // Reload room but room is already not in favorites
+    cy.fixture("room.json").then((room) => {
+      room.data.owner = {
+        id: 2,
+        name: "Max Doe",
+      };
+      room.data.description = "<p>Test</p>";
+      room.data.allow_membership = true;
+      room.data.is_favorite = true;
+
+      cy.intercept("GET", "api/v1/rooms/abc-def-123", {
+        statusCode: 200,
+        body: room,
+      }).as("roomRequest");
+    });
+
+    cy.reload();
+
+    cy.wait("@roomRequest");
+
+    // Test remove from favorites with 404 error (room not found)
+    cy.interceptRoomIndexRequests();
+
+    cy.intercept("DELETE", "api/v1/rooms/abc-def-123/favorites", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "room",
+        ids: ["abc-def-123"],
+      },
+    }).as("deleteFavoritesRequest");
+
+    cy.get('[data-test="room-favorites-button"]')
+      .should("have.attr", "aria-label", "rooms.favorites.remove")
+      .click();
+
+    cy.wait("@deleteFavoritesRequest");
+
+    // Check that redirect worked and error message is shown
+    cy.url()
+      .should("include", "/rooms")
+      .and("not.include", "rooms/abc-def-123");
+
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
   });
 
   it("visit with guest forbidden", function () {
@@ -2786,6 +3062,9 @@ describe("Room View general", function () {
   });
 
   it("visit with room not found", function () {
+    // Try with logged in user
+    cy.interceptRoomIndexRequests();
+
     cy.intercept("GET", "api/v1/rooms/abc-def-123", {
       statusCode: 404,
       body: {
@@ -2795,9 +3074,30 @@ describe("Room View general", function () {
 
     cy.visit("/rooms/abc-def-123");
 
+    // Check redirect to room index page
+    cy.url()
+      .should("include", "/rooms")
+      .should("not.include", "/rooms/abc-def-123");
+
+    cy.checkToastMessage([
+      'app.flash.server_error.message_{"message":"No query results for model [App\\\\Room] abc-def-123"}',
+      'app.flash.server_error.error_code_{"statusCode":404}',
+    ]);
+
+    // Try with guest
+    cy.intercept("GET", "api/v1/currentUser", {});
+
+    cy.visit("/rooms/abc-def-123");
+
+    // Check redirect to 404 page
     cy.url()
       .should("include", "/404")
       .should("not.include", "/rooms/abc-def-123");
+
+    cy.checkToastMessage([
+      'app.flash.server_error.message_{"message":"No query results for model [App\\\\Room] abc-def-123"}',
+      'app.flash.server_error.error_code_{"statusCode":404}',
+    ]);
   });
 
   it("auto-reload", function () {
@@ -2919,7 +3219,9 @@ describe("Room View general", function () {
 
     cy.wait("@roomRequest");
 
-    // Test reload with room not found
+    // Test reload with room not found and guest user
+    cy.interceptRoomIndexRequests();
+
     cy.intercept("GET", "api/v1/rooms/abc-def-123", {
       statusCode: 404,
       body: {
@@ -2930,9 +3232,50 @@ describe("Room View general", function () {
     cy.get('[data-test="reload-room-button"]').click();
     cy.wait("@roomRequest");
 
+    // Check redirect to 404 page worked
     cy.url()
       .should("include", "/404")
       .should("not.include", "/rooms/abc-def-123");
+
+    cy.checkToastMessage([
+      'app.flash.server_error.message_{"message":"No query results for model [App\\\\Room] abc-def-123"}',
+      'app.flash.server_error.error_code_{"statusCode":404}',
+    ]);
+
+    // Test reload with room not found and authenticated user
+    cy.intercept("GET", "api/v1/currentUser", { fixture: "currentUser.json" });
+    cy.fixture("room.json").then((room) => {
+      room.data.allow_membership = true;
+
+      cy.intercept("GET", "api/v1/rooms/abc-def-123", {
+        statusCode: 200,
+        body: room,
+      }).as("roomRequest");
+    });
+
+    cy.visit("/rooms/abc-def-123");
+    cy.wait("@roomRequest");
+    cy.contains("Meeting One").should("be.visible");
+
+    cy.intercept("GET", "api/v1/rooms/abc-def-123", {
+      statusCode: 404,
+      body: {
+        message: "No query results for model [App\\Room] abc-def-123",
+      },
+    }).as("roomRequest");
+
+    cy.get('[data-test="reload-room-button"]').click();
+    cy.wait("@roomRequest");
+
+    // Check redirect to room index page worked
+    cy.url()
+      .should("include", "/rooms")
+      .should("not.include", "/rooms/abc-def-123");
+
+    cy.checkToastMessage([
+      'app.flash.server_error.message_{"message":"No query results for model [App\\\\Room] abc-def-123"}',
+      'app.flash.server_error.error_code_{"statusCode":404}',
+    ]);
   });
 
   it("reload with access code errors", function () {
diff --git a/tests/Frontend/e2e/RoomsViewHistory.cy.js b/tests/Frontend/e2e/RoomsViewHistory.cy.js
index 7af126f5e..1936dd962 100644
--- a/tests/Frontend/e2e/RoomsViewHistory.cy.js
+++ b/tests/Frontend/e2e/RoomsViewHistory.cy.js
@@ -496,6 +496,36 @@ describe("Rooms view history", function () {
       "api/v1/rooms/abc-def-123/meetings*",
       "history",
     );
+
+    // Reload page
+    cy.interceptRoomViewRequests();
+    cy.reload();
+
+    cy.wait("@roomRequest");
+
+    // Check with 404 error (room not found)
+    cy.interceptRoomIndexRequests();
+
+    cy.intercept("GET", "api/v1/rooms/abc-def-123/meetings*", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "room",
+        ids: ["abc-def-123"],
+      },
+    }).as("roomHistoryRequest");
+
+    cy.get("#tab-history").click();
+    cy.wait("@roomHistoryRequest");
+
+    // Check that redirect to room index page works and that error message is shown
+    cy.url()
+      .should("include", "/rooms")
+      .and("not.include", "rooms/abc-def-123");
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
   });
 
   it("load history page out of range", function () {
diff --git a/tests/Frontend/e2e/RoomsViewHistoryMeetingActions.cy.js b/tests/Frontend/e2e/RoomsViewHistoryMeetingActions.cy.js
index edd734fd7..6a9fb3185 100644
--- a/tests/Frontend/e2e/RoomsViewHistoryMeetingActions.cy.js
+++ b/tests/Frontend/e2e/RoomsViewHistoryMeetingActions.cy.js
@@ -139,8 +139,9 @@ describe("Rooms view history meeting actions", function () {
       {
         statusCode: 404,
         body: {
-          message:
-            "No query results for model [App\\Models\\Meeting] 3a3e504a-d2c4-431c-8ca1-a62598e66761",
+          message: "model_not_found",
+          model: "meeting",
+          ids: ["3a3e504a-d2c4-431c-8ca1-a62598e66761"],
         },
       },
     ).as("statsRequest");
@@ -154,8 +155,8 @@ describe("Rooms view history meeting actions", function () {
 
     // Check that error message is shown
     cy.checkToastMessage([
-      'app.flash.server_error.message_{"message":"No query results for model [App\\\\Models\\\\Meeting] 3a3e504a-d2c4-431c-8ca1-a62598e66761"}',
-      'app.flash.server_error.error_code_{"statusCode":404}',
+      'app.flash.model_not_found.title_{"model":"app.model.meeting"}',
+      'app.flash.model_not_found.details_{"ids":"3a3e504a-d2c4-431c-8ca1-a62598e66761"}',
     ]);
 
     // Check if dialog is closed
@@ -477,8 +478,9 @@ describe("Rooms view history meeting actions", function () {
       {
         statusCode: 404,
         body: {
-          message:
-            "No query results for model [App\\Models\\Meeting] 3a3e504a-d2c4-431c-8ca1-a62598e66761",
+          message: "model_not_found",
+          model: "meeting",
+          ids: ["3a3e504a-d2c4-431c-8ca1-a62598e66761"],
         },
       },
     ).as("attendanceRequest");
@@ -492,8 +494,8 @@ describe("Rooms view history meeting actions", function () {
 
     // Check that error message is shown
     cy.checkToastMessage([
-      'app.flash.server_error.message_{"message":"No query results for model [App\\\\Models\\\\Meeting] 3a3e504a-d2c4-431c-8ca1-a62598e66761"}',
-      'app.flash.server_error.error_code_{"statusCode":404}',
+      'app.flash.model_not_found.title_{"model":"app.model.meeting"}',
+      'app.flash.model_not_found.details_{"ids":"3a3e504a-d2c4-431c-8ca1-a62598e66761"}',
     ]);
 
     // Check if dialog is closed
diff --git a/tests/Frontend/e2e/RoomsViewMeetings.cy.js b/tests/Frontend/e2e/RoomsViewMeetings.cy.js
index bf8c83785..b253e292d 100644
--- a/tests/Frontend/e2e/RoomsViewMeetings.cy.js
+++ b/tests/Frontend/e2e/RoomsViewMeetings.cy.js
@@ -1344,6 +1344,56 @@ describe("Rooms view meetings", function () {
       "have.text",
       "rooms.start",
     );
+
+    // Reload page
+    cy.fixture("room.json").then((room) => {
+      room.data.last_meeting = {
+        start: "2023-08-21T08:18:28.000000Z",
+        end: null,
+      };
+
+      cy.intercept("GET", "api/v1/rooms/abc-def-123", {
+        statusCode: 200,
+        body: room,
+      }).as("roomRequest");
+    });
+    cy.reload();
+
+    // Test with 404 error (room not found)
+    cy.interceptRoomIndexRequests();
+
+    cy.intercept("POST", "/api/v1/rooms/abc-def-123/join*", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "room",
+        ids: ["abc-def-123"],
+      },
+    }).as("joinRequest");
+
+    // Try to join meeting
+    cy.get('[data-test="room-join-button"]').click();
+
+    cy.get('[data-test="room-join-dialog"]')
+      .should("be.visible")
+      .within(() => {
+        cy.get("#record-attendance-agreement").should("not.be.checked").click();
+        cy.get("#record-agreement").should("not.be.checked").click();
+        cy.get("#record-video-agreement").should("not.be.checked").click();
+        cy.get('[data-test="dialog-continue-button"]').click();
+      });
+
+    cy.wait("@joinRequest");
+
+    // Check that redirect to room index page worked and error message is shown
+    cy.url()
+      .should("include", "/rooms")
+      .and("not.include", "/rooms/abc-def-123");
+
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
   });
 
   it("join meeting load requirements errors", function () {
@@ -1465,6 +1515,7 @@ describe("Rooms view meetings", function () {
         message: "require_code",
       },
     }).as("preJoinRequest");
+    cy.interceptRoomFilesRequest();
 
     cy.fixture("room.json").then((room) => {
       room.data.last_meeting = {
@@ -1552,6 +1603,46 @@ describe("Rooms view meetings", function () {
 
     // Check dialog is closed
     cy.get('[data-test="room-join-dialog"]').should("not.exist");
+
+    // Reload room
+    cy.fixture("room.json").then((room) => {
+      room.data.last_meeting = {
+        start: "2023-08-21T08:18:28.000000Z",
+        end: null,
+      };
+      room.data.current_user = null;
+
+      cy.intercept("GET", "api/v1/rooms/abc-def-123*", {
+        statusCode: 200,
+        body: room,
+      }).as("roomRequest");
+    });
+
+    cy.visit("/rooms/abc-def-123");
+
+    cy.wait("@roomRequest");
+
+    // Check with 404 error (room not found)
+    cy.intercept("OPTIONS", "api/v1/rooms/abc-def-123/join*", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "room",
+        ids: ["abc-def-123"],
+      },
+    }).as("preJoinRequest");
+
+    // Try to join meeting
+    cy.get('[data-test="room-join-button"]').click();
+    cy.wait("@preJoinRequest");
+
+    // Check that redirect to 404 page worked and error message is shown
+    cy.url().should("include", "/404").and("not.include", "/rooms/abc-def-123");
+
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
   });
 
   it("join running meeting with dark mode", function () {
@@ -2913,6 +3004,48 @@ describe("Rooms view meetings", function () {
       "eq",
       `${Cypress.expose("redirectBaseUrl")}/bigbluebutton?foo=a&bar=b`,
     );
+
+    // Reload room
+    cy.intercept("GET", "api/v1/rooms/abc-def-123", {
+      fixture: "room.json",
+    }).as("roomRequest");
+
+    cy.visit("/rooms/abc-def-123");
+
+    cy.wait("@roomRequest");
+
+    // Try with 404 error (room not found)
+    cy.interceptRoomIndexRequests();
+    cy.intercept("POST", "/api/v1/rooms/abc-def-123/start*", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "room",
+        ids: ["abc-def-123"],
+      },
+    }).as("startRequest");
+
+    cy.get('[data-test="room-start-button"]').click();
+    cy.get('[data-test="room-join-dialog"]')
+      .should("be.visible")
+      .within(() => {
+        cy.get("#record-attendance-agreement").should("not.be.checked").click();
+        cy.get("#record-agreement").should("not.be.checked").click();
+        cy.get("#record-video-agreement").should("not.be.checked").click();
+        cy.get('[data-test="dialog-continue-button"]').click();
+      });
+
+    cy.wait("@startRequest");
+
+    // Check if redirect worked and error message is shown
+    cy.url()
+      .should("include", "/rooms")
+      .and("not.include", "/rooms/abc-def-123");
+
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
   });
 
   it("start meeting load requirements errors", function () {
@@ -3141,6 +3274,28 @@ describe("Rooms view meetings", function () {
 
     // Check dialog is closed
     cy.get('[data-test="room-join-dialog"]').should("not.exist");
+
+    // Test 404 error (room not found)
+    cy.intercept("OPTIONS", "api/v1/rooms/abc-def-123/start*", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "room",
+        ids: ["abc-def-123"],
+      },
+    }).as("preStartRequest");
+
+    // Try to start meeting
+    cy.get('[data-test="room-start-button"]').click();
+    cy.wait("@preStartRequest");
+
+    // Check if redirect worked and error message is shown
+    cy.url().should("include", "/404").and("not.include", "/rooms/abc-def-123");
+
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
   });
 
   it("start meeting with dark mode", function () {
diff --git a/tests/Frontend/e2e/RoomsViewMembers.cy.js b/tests/Frontend/e2e/RoomsViewMembers.cy.js
index 3f1215a14..93873acd8 100644
--- a/tests/Frontend/e2e/RoomsViewMembers.cy.js
+++ b/tests/Frontend/e2e/RoomsViewMembers.cy.js
@@ -484,6 +484,35 @@ describe("Rooms view members", function () {
       "api/v1/rooms/abc-def-123/member*",
       "members",
     );
+
+    // Reload room page
+    cy.interceptRoomViewRequests();
+    cy.reload();
+
+    // Test 404 error (room not found)
+    cy.interceptRoomIndexRequests();
+    cy.intercept("GET", "api/v1/rooms/abc-def-123/member*", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "room",
+        ids: ["abc-def-123"],
+      },
+    }).as("roomMembersRequest");
+
+    cy.get("#tab-members").click();
+
+    cy.wait("@roomMembersRequest");
+
+    // Check that redirect to room index page works and error message is shown
+    cy.url()
+      .should("include", "/rooms")
+      .and("not.include", "/rooms/abc-def-123");
+
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
   });
 
   it("load members page out of range", function () {
diff --git a/tests/Frontend/e2e/RoomsViewMembersBulkActions.cy.js b/tests/Frontend/e2e/RoomsViewMembersBulkActions.cy.js
index 52a7fd3e7..1a9dbb172 100644
--- a/tests/Frontend/e2e/RoomsViewMembersBulkActions.cy.js
+++ b/tests/Frontend/e2e/RoomsViewMembersBulkActions.cy.js
@@ -408,6 +408,47 @@ describe("Rooms view members bulk actions", function () {
       "api/v1/rooms/abc-def-123/member/bulk",
       "members",
     );
+
+    // Reload room page
+    cy.interceptRoomViewRequests();
+    cy.reload();
+
+    cy.wait("@roomRequest");
+
+    cy.get("#tab-members").should("be.visible").click();
+
+    // Select all users
+    cy.get('[data-test="room-members-select-all-checkbox"]').click();
+
+    // Test bulk edit with 404 error (room not found)
+    cy.interceptRoomIndexRequests();
+    cy.intercept("PUT", "api/v1/rooms/abc-def-123/member/bulk", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "room",
+        ids: ["abc-def-123"],
+      },
+    }).as("bulkEditRequest");
+
+    cy.get('[data-test="room-members-bulk-edit-button"]')
+      .should("be.visible")
+      .click();
+
+    cy.get('[data-test="room-members-bulk-edit-dialog"]').should("be.visible");
+    cy.get('[data-test="dialog-save-button"]').click();
+
+    cy.wait("@bulkEditRequest");
+
+    // Check that redirect to room index page worked and error message is shown
+    cy.url()
+      .should("include", "/rooms")
+      .and("not.include", "rooms/abc-def-123");
+
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
   });
 
   it("bulk delete members", function () {
@@ -682,6 +723,50 @@ describe("Rooms view members bulk actions", function () {
       "api/v1/rooms/abc-def-123/member/bulk",
       "members",
     );
+
+    // Reload room page
+    cy.interceptRoomViewRequests();
+    cy.reload();
+
+    cy.wait("@roomRequest");
+
+    cy.get("#tab-members").should("be.visible").click();
+
+    // Select all users
+    cy.get('[data-test="room-members-select-all-checkbox"] > input').click();
+
+    // Test bulk delete with 404 error (room not found)
+    cy.interceptRoomIndexRequests();
+
+    cy.intercept("DELETE", "api/v1/rooms/abc-def-123/member/bulk", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "room",
+        ids: ["abc-def-123"],
+      },
+    }).as("bulkDeleteRequest");
+
+    cy.get('[data-test="room-members-bulk-delete-button"]')
+      .should("be.visible")
+      .click();
+
+    cy.get('[data-test="room-members-bulk-delete-dialog"]').should(
+      "be.visible",
+    );
+    cy.get('[data-test="dialog-continue-button"]').click();
+
+    cy.wait("@bulkDeleteRequest");
+
+    // Check that redirect to room index page worked and error message is shown
+    cy.url()
+      .should("include", "/rooms")
+      .and("not.include", "rooms/abc-def-123");
+
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
   });
 
   it("bulk import members", function () {
@@ -1386,5 +1471,48 @@ describe("Rooms view members bulk actions", function () {
       "api/v1/rooms/abc-def-123/member/bulk",
       "members",
     );
+
+    // Reload room page
+    cy.interceptRoomViewRequests();
+    cy.reload();
+
+    cy.wait("@roomRequest");
+
+    cy.get("#tab-members").should("be.visible").click();
+
+    // Test bulk import with 404 error (room not found)
+    cy.interceptRoomIndexRequests();
+
+    cy.intercept("POST", "api/v1/rooms/abc-def-123/member/bulk", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "room",
+        ids: ["abc-def-123"],
+      },
+    }).as("bulkImportRequest");
+
+    cy.get('[data-test="room-members-add-button"]').click();
+    cy.get("#overlay_menu_1")
+      .should("have.text", "rooms.members.bulk_import_users")
+      .click();
+
+    cy.get('[data-test="room-members-bulk-import-dialog"]').should(
+      "be.visible",
+    );
+    cy.get("#user-emails").type("\n");
+    cy.get('[data-test="dialog-continue-button"]').click();
+
+    cy.wait("@bulkImportRequest");
+
+    // Check that redirect to room index page worked and error message is shown
+    cy.url()
+      .should("include", "/rooms")
+      .and("not.include", "rooms/abc-def-123");
+
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
   });
 });
diff --git a/tests/Frontend/e2e/RoomsViewMembersMemberActions.cy.js b/tests/Frontend/e2e/RoomsViewMembersMemberActions.cy.js
index d2fea1dd4..0947f2ca6 100644
--- a/tests/Frontend/e2e/RoomsViewMembersMemberActions.cy.js
+++ b/tests/Frontend/e2e/RoomsViewMembersMemberActions.cy.js
@@ -432,6 +432,50 @@ describe("Rooms view members member actions", function () {
       "/api/v1/rooms/abc-def-123/member",
       "members",
     );
+
+    // Reload room page
+    cy.interceptRoomViewRequests();
+    cy.interceptRoomMembersRequest();
+    cy.reload();
+
+    cy.wait("@roomRequest");
+    cy.wait("@roomMembersRequest");
+
+    cy.get("#tab-members").click();
+
+    // Test add new member with 404 error (room not found)
+    cy.interceptRoomIndexRequests();
+
+    cy.get('[data-test="room-members-add-button"]').click();
+
+    cy.get("#overlay_menu_0")
+      .should("have.text", "rooms.members.add_single_user")
+      .click();
+
+    cy.get('[data-test="room-members-add-single-dialog"]').should("be.visible");
+
+    cy.intercept("POST", "/api/v1/rooms/abc-def-123/member", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "room",
+        ids: ["abc-def-123"],
+      },
+    }).as("addUserRequest");
+
+    cy.get('[data-test="dialog-save-button"]').click();
+
+    cy.wait("@addUserRequest");
+
+    // Check that user is redirected to room index page and error message is shown
+    cy.url()
+      .should("include", "/rooms")
+      .and("not.include", "rooms/abc-def-123");
+
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
   });
 
   it("edit member", function () {
@@ -536,9 +580,11 @@ describe("Rooms view members member actions", function () {
 
     // Check with member gone
     cy.intercept("PUT", "/api/v1/rooms/abc-def-123/member/5", {
-      statusCode: 410,
+      statusCode: 404,
       body: {
-        message: "The person is not a member of this room (anymore).",
+        message: "model_not_found",
+        model: "user",
+        ids: [5],
       },
     }).as("editUserRequest");
 
@@ -566,10 +612,7 @@ describe("Rooms view members member actions", function () {
     cy.get('[data-test="room-member-item"]').should("have.length", 2);
 
     // Check that error message is shown
-    cy.checkToastMessage([
-      'app.flash.server_error.message_{"message":"The person is not a member of this room (anymore)."}',
-      'app.flash.server_error.error_code_{"statusCode":410}',
-    ]);
+    cy.checkToastMessage("app.errors.not_member_of_room");
 
     // Check with 422 error
     cy.get('[data-test="room-member-item"]')
@@ -636,6 +679,49 @@ describe("Rooms view members member actions", function () {
       "/api/v1/rooms/abc-def-123/member/6",
       "members",
     );
+
+    // Reload room page
+    cy.interceptRoomViewRequests();
+    cy.interceptRoomMembersRequest();
+    cy.reload();
+
+    cy.wait("@roomRequest");
+
+    cy.get("#tab-members").click();
+    cy.wait("@roomMembersRequest");
+
+    // Test edit member with 404 error (room not found)
+    cy.interceptRoomIndexRequests();
+
+    cy.get('[data-test="room-member-item"]')
+      .eq(0)
+      .find('[data-test="room-members-edit-button"]')
+      .click();
+
+    cy.get('[data-test="room-members-edit-dialog"]').should("be.visible");
+
+    cy.intercept("PUT", "/api/v1/rooms/abc-def-123/member/5", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "room",
+        ids: ["abc-def-123"],
+      },
+    }).as("editUserRequest");
+
+    cy.get('[data-test="dialog-save-button"]').click();
+
+    cy.wait("@editUserRequest");
+
+    // Check that user is redirected to room index page and error message is shown
+    cy.url()
+      .should("include", "/rooms")
+      .and("not.include", "rooms/abc-def-123");
+
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
   });
 
   it("delete member", function () {
@@ -721,9 +807,11 @@ describe("Rooms view members member actions", function () {
 
     // Check delete with member gone
     cy.intercept("DELETE", "/api/v1/rooms/abc-def-123/member/5", {
-      statusCode: 410,
+      statusCode: 404,
       body: {
-        message: "The person is not a member of this room (anymore).",
+        message: "model_not_found",
+        model: "user",
+        ids: [5],
       },
     }).as("deleteMemberRequest");
 
@@ -749,10 +837,7 @@ describe("Rooms view members member actions", function () {
     cy.get('[data-test="room-member-item"]').should("have.length", 2);
 
     // Check that error message is shown
-    cy.checkToastMessage([
-      'app.flash.server_error.message_{"message":"The person is not a member of this room (anymore)."}',
-      'app.flash.server_error.error_code_{"statusCode":410}',
-    ]);
+    cy.checkToastMessage("app.errors.not_member_of_room");
 
     // Check with 500 error
     cy.get('[data-test="room-member-item"]')
@@ -797,5 +882,48 @@ describe("Rooms view members member actions", function () {
       "/api/v1/rooms/abc-def-123/member/6",
       "members",
     );
+
+    // Reload room page
+    cy.interceptRoomViewRequests();
+    cy.interceptRoomMembersRequest();
+
+    cy.reload();
+
+    cy.wait("@roomRequest");
+    cy.get("#tab-members").click();
+    cy.wait("@roomMembersRequest");
+
+    // Test delete member with room index error (room not found)
+    cy.interceptRoomIndexRequests();
+
+    cy.get('[data-test="room-member-item"]')
+      .eq(0)
+      .find('[data-test="room-members-delete-button"]')
+      .click();
+
+    cy.get('[data-test="room-members-delete-dialog"]').should("be.visible");
+
+    cy.intercept("DELETE", "/api/v1/rooms/abc-def-123/member/5", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "room",
+        ids: ["abc-def-123"],
+      },
+    }).as("deleteMemberRequest");
+
+    cy.get('[data-test="dialog-continue-button"]').click();
+
+    cy.wait("@deleteMemberRequest");
+
+    // Check that user is redirected to room index page and error message is shown
+    cy.url()
+      .should("include", "/rooms")
+      .and("not.include", "rooms/abc-def-123");
+
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
   });
 });
diff --git a/tests/Frontend/e2e/RoomsViewPersonalizedLinks.cy.js b/tests/Frontend/e2e/RoomsViewPersonalizedLinks.cy.js
index 721f7b187..23c4c59ff 100644
--- a/tests/Frontend/e2e/RoomsViewPersonalizedLinks.cy.js
+++ b/tests/Frontend/e2e/RoomsViewPersonalizedLinks.cy.js
@@ -496,6 +496,44 @@ describe("Rooms view personalized links", function () {
       "api/v1/rooms/abc-def-123/personalizedLinks*",
       "tokens",
     );
+
+    // Reload room page
+    cy.interceptRoomViewRequests();
+    cy.reload();
+
+    cy.wait("@roomRequest");
+
+    // Check with 404 error (room not found)
+    cy.interceptRoomIndexRequests();
+
+    cy.intercept(
+      {
+        method: "GET",
+        url: "api/v1/rooms/abc-def-123/personalizedLinks*",
+      },
+      {
+        statusCode: 404,
+        body: {
+          message: "model_not_found",
+          model: "room",
+          ids: ["abc-def-123"],
+        },
+      },
+    ).as("roomPersonalizedLinksRequest");
+
+    cy.get("#tab-tokens").click();
+
+    cy.wait("@roomPersonalizedLinksRequest");
+
+    // Check that redirect to room index page worked and error message is shown
+    cy.url()
+      .should("include", "/rooms")
+      .and("not.include", "rooms/abc-def-123");
+
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
   });
 
   it("load personalized links page out of range", function () {
diff --git a/tests/Frontend/e2e/RoomsViewPersonalizedLinksTokenActions.cy.js b/tests/Frontend/e2e/RoomsViewPersonalizedLinksTokenActions.cy.js
index ba56784e5..8cdf74b72 100644
--- a/tests/Frontend/e2e/RoomsViewPersonalizedLinksTokenActions.cy.js
+++ b/tests/Frontend/e2e/RoomsViewPersonalizedLinksTokenActions.cy.js
@@ -234,6 +234,43 @@ describe("Rooms view personalized links actions", function () {
       "/api/v1/rooms/abc-def-123/personalizedLinks/",
       "tokens",
     );
+
+    // Reload room page
+    cy.interceptRoomViewRequests();
+    cy.reload();
+    cy.get("#tab-tokens").should("be.visible").click();
+    cy.wait("@roomRequest");
+    cy.wait("@roomPersonalizedLinksRequest");
+
+    // Test add personalized link with 404 error (room not found)
+    cy.interceptRoomIndexRequests();
+
+    cy.intercept("POST", "/api/v1/rooms/abc-def-123/personalizedLinks/", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "room",
+        ids: ["abc-def-123"],
+      },
+    }).as("addLinkRequest");
+
+    cy.get('[data-test="room-personalized-links-add-button"]').click();
+    cy.get('[data-test="room-personalized-links-add-dialog"]').should(
+      "be.visible",
+    );
+    cy.get('[data-test="dialog-save-button"]').click();
+
+    cy.wait("@addLinkRequest");
+
+    // Check that redirect to room index page works and error message is shown
+    cy.url()
+      .should("include", "/rooms")
+      .and("not.include", "/rooms/abc-def-123");
+
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
   });
 
   it("edit personalized link", function () {
@@ -395,7 +432,9 @@ describe("Rooms view personalized links actions", function () {
     cy.intercept("PUT", "/api/v1/rooms/abc-def-123/personalizedLinks/3", {
       statusCode: 404,
       body: {
-        message: "No query results for model",
+        message: "model_not_found",
+        model: "room_personalized_link",
+        ids: [3],
       },
     }).as("editLinkRequest");
 
@@ -523,6 +562,46 @@ describe("Rooms view personalized links actions", function () {
       "/api/v1/rooms/abc-def-123/personalizedLinks/1",
       "tokens",
     );
+
+    // Reload room page
+    cy.interceptRoomViewRequests();
+    cy.reload();
+    cy.get("#tab-tokens").should("be.visible").click();
+    cy.wait("@roomRequest");
+    cy.wait("@roomPersonalizedLinksRequest");
+
+    // Test edit personalized link with 404 error (room not found)
+    cy.interceptRoomIndexRequests();
+
+    cy.intercept("PUT", "/api/v1/rooms/abc-def-123/personalizedLinks/1", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "room",
+        ids: ["abc-def-123"],
+      },
+    }).as("editLinkRequest");
+
+    cy.get('[data-test="room-personalized-link-item"]')
+      .eq(0)
+      .find('[data-test="room-personalized-links-edit-button"]')
+      .click();
+    cy.get('[data-test="room-personalized-links-edit-dialog"]').should(
+      "be.visible",
+    );
+    cy.get('[data-test="dialog-save-button"]').click();
+
+    cy.wait("@editLinkRequest");
+
+    // Check that redirect to room index page works and error message is shown
+    cy.url()
+      .should("include", "/rooms")
+      .and("not.include", "/rooms/abc-def-123");
+
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
   });
 
   it("delete personalized link", function () {
@@ -629,7 +708,9 @@ describe("Rooms view personalized links actions", function () {
     cy.intercept("DELETE", "/api/v1/rooms/abc-def-123/personalizedLinks/3", {
       statusCode: 404,
       body: {
-        message: "No query results for model",
+        message: "model_not_found",
+        model: "room_personalized_link",
+        ids: [3],
       },
     }).as("deleteLinkRequest");
 
@@ -716,6 +797,46 @@ describe("Rooms view personalized links actions", function () {
       "/api/v1/rooms/abc-def-123/personalizedLinks/1",
       "tokens",
     );
+
+    // Reload room page
+    cy.interceptRoomViewRequests();
+    cy.reload();
+    cy.get("#tab-tokens").should("be.visible").click();
+    cy.wait("@roomRequest");
+    cy.wait("@roomPersonalizedLinksRequest");
+
+    // Test delete personalized link with 404 error (room not found)
+    cy.interceptRoomIndexRequests();
+
+    cy.intercept("DELETE", "/api/v1/rooms/abc-def-123/personalizedLinks/1", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "room",
+        ids: ["abc-def-123"],
+      },
+    }).as("deleteLinkRequest");
+
+    cy.get('[data-test="room-personalized-link-item"]')
+      .eq(0)
+      .find('[data-test="room-personalized-links-delete-button"]')
+      .click();
+    cy.get('[data-test="room-personalized-links-delete-dialog"]').should(
+      "be.visible",
+    );
+    cy.get('[data-test="dialog-continue-button"]').click();
+
+    cy.wait("@deleteLinkRequest");
+
+    // Check that redirect to room index page works and error message is shown
+    cy.url()
+      .should("include", "/rooms")
+      .and("not.include", "/rooms/abc-def-123");
+
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
   });
 
   it("copy personalized link", function () {
diff --git a/tests/Frontend/e2e/RoomsViewRecordings.cy.js b/tests/Frontend/e2e/RoomsViewRecordings.cy.js
index 79e4a75fd..322643edd 100644
--- a/tests/Frontend/e2e/RoomsViewRecordings.cy.js
+++ b/tests/Frontend/e2e/RoomsViewRecordings.cy.js
@@ -758,6 +758,56 @@ describe("Rooms view recordings", function () {
     cy.get('[data-test="paginator-page"]')
       .eq(0)
       .should("have.attr", "data-p-active", "true");
+
+    // Check with 404 error (room not found) as authenticated user
+    cy.interceptRoomIndexRequests();
+
+    cy.intercept("GET", "api/v1/rooms/abc-def-123/recordings*", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "room",
+        ids: ["abc-def-123"],
+      },
+    }).as("roomRecordingsRequest");
+
+    // Reload page
+    cy.reload();
+
+    cy.wait("@roomRecordingsRequest");
+
+    // Check that redirect to room index page worked and error message is shown
+    cy.url()
+      .should("include", "/rooms")
+      .and("not.include", "/rooms/abc-def-123");
+
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
+
+    // Check with 404 error (room not found) as guest
+    cy.intercept("GET", "api/v1/currentUser", {});
+    cy.fixture("room.json").then((room) => {
+      room.data.current_user = null;
+
+      cy.intercept("GET", "api/v1/rooms/abc-def-123*", {
+        statusCode: 200,
+        body: room,
+      }).as("roomRequest");
+
+      cy.visit("/rooms/abc-def-123#tab=recordings");
+
+      cy.wait("@roomRecordingsRequest");
+    });
+
+    // Check that redirect to 404 page worked and error message is shown
+    cy.url().should("include", "/404").and("not.include", "/rooms/abc-def-123");
+
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
   });
 
   it("load recordings page out of range", function () {
diff --git a/tests/Frontend/e2e/RoomsViewRecordingsRecordingActions.cy.js b/tests/Frontend/e2e/RoomsViewRecordingsRecordingActions.cy.js
index 0aeee1067..4519e7c4e 100644
--- a/tests/Frontend/e2e/RoomsViewRecordingsRecordingActions.cy.js
+++ b/tests/Frontend/e2e/RoomsViewRecordingsRecordingActions.cy.js
@@ -879,7 +879,9 @@ describe("Rooms view recordings recording actions", function () {
       {
         statusCode: 404,
         body: {
-          message: "No query results for model",
+          message: "model_not_found",
+          model: "recording",
+          ids: ["f9569db6d5e8fb2fd2f57d367d5482b36837b9d8-1663666775"],
         },
       },
     ).as("deleteRecordingRequest");
@@ -965,6 +967,51 @@ describe("Rooms view recordings recording actions", function () {
       "api/v1/rooms/abc-def-123/recordings/e0cfa18c5fd75a42bd7947d8549321b03abf1daf-1660728035",
       "recordings",
     );
+
+    // Reload room
+    cy.interceptRoomViewRequests();
+    cy.interceptRoomRecordingsRequests();
+
+    cy.reload();
+    cy.get("#tab-recordings").should("be.visible").click();
+
+    // Check with 404 error (room not found)
+    cy.interceptRoomIndexRequests();
+
+    cy.intercept(
+      "DELETE",
+      "api/v1/rooms/abc-def-123/recordings/e0cfa18c5fd75a42bd7947d8549321b03abf1daf-1660728035",
+      {
+        statusCode: 404,
+        body: {
+          message: "model_not_found",
+          model: "room",
+          ids: ["abc-def-123"],
+        },
+      },
+    ).as("deleteRecordingRequest");
+
+    cy.get('[data-test="room-recording-item"]')
+      .eq(0)
+      .find('[data-test="room-recordings-delete-button"]')
+      .click();
+
+    cy.get('[data-test="room-recordings-delete-dialog"]')
+      .should("be.visible")
+      .find('[data-test="dialog-continue-button"]')
+      .click();
+
+    cy.wait("@deleteRecordingRequest");
+
+    // Check that redirect to room index page worked and error message is shown
+    cy.url()
+      .should("include", "/rooms")
+      .and("not.include", "rooms/abc-def-123");
+
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
   });
 
   it("edit recording", function () {
@@ -1174,7 +1221,9 @@ describe("Rooms view recordings recording actions", function () {
       {
         statusCode: 404,
         body: {
-          message: "No query results for model",
+          message: "model_not_found",
+          model: "recording",
+          ids: ["f9569db6d5e8fb2fd2f57d367d5482b36837b9d8-1663666775"],
         },
       },
     ).as("editRecordingRequest");
@@ -1318,5 +1367,52 @@ describe("Rooms view recordings recording actions", function () {
       "api/v1/rooms/abc-def-123/recordings/e0cfa18c5fd75a42bd7947d8549321b03abf1daf-1660728035",
       "recordings",
     );
+
+    // Reload room
+    cy.interceptRoomViewRequests();
+    cy.interceptRoomRecordingsRequests();
+
+    cy.reload();
+    cy.get("#tab-recordings").should("be.visible").click();
+
+    cy.wait("@roomRecordingsRequest");
+
+    // Check with 404 error (room not found)
+    cy.interceptRoomIndexRequests();
+
+    cy.intercept(
+      "PUT",
+      "api/v1/rooms/abc-def-123/recordings/e0cfa18c5fd75a42bd7947d8549321b03abf1daf-1660728035",
+      {
+        statusCode: 404,
+        body: {
+          message: "model_not_found",
+          model: "room",
+          ids: ["abc-def-123"],
+        },
+      },
+    ).as("editRecordingRequest");
+
+    cy.get('[data-test="room-recording-item"]')
+      .eq(0)
+      .find('[data-test="room-recordings-edit-button"]')
+      .click();
+
+    cy.get('[data-test="room-recordings-edit-dialog"]')
+      .should("be.visible")
+      .find('[data-test="dialog-save-button"]')
+      .click();
+
+    cy.wait("@editRecordingRequest");
+
+    // Check that redirect to room index page worked and error message is shown
+    cy.url()
+      .should("include", "/rooms")
+      .and("not.include", "rooms/abc-def-123");
+
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
   });
 });
diff --git a/tests/Frontend/e2e/RoomsViewSettings.cy.js b/tests/Frontend/e2e/RoomsViewSettings.cy.js
index fb9eeed22..2bb2bd1ef 100644
--- a/tests/Frontend/e2e/RoomsViewSettings.cy.js
+++ b/tests/Frontend/e2e/RoomsViewSettings.cy.js
@@ -414,6 +414,38 @@ describe("Rooms view settings", function () {
       "api/v1/rooms/abc-def-123/settings",
       "settings",
     );
+
+    // Reload room
+    cy.interceptRoomViewRequests();
+    cy.reload();
+
+    cy.wait("@roomRequest");
+
+    // Check with 404 error (room not found)
+    cy.interceptRoomIndexRequests();
+
+    cy.intercept("GET", "api/v1/rooms/abc-def-123/settings", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "room",
+        ids: ["abc-def-123"],
+      },
+    }).as("roomSettingsRequest");
+
+    cy.get("#tab-settings").click();
+
+    cy.wait("@roomSettingsRequest");
+
+    // Check that redirect to room index page worked and error message is shown
+    cy.url()
+      .should("include", "/rooms")
+      .and("not.include", "rooms/abc-def-123");
+
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
   });
 
   it("load settings with different permissions", function () {
@@ -1370,6 +1402,8 @@ describe("Rooms view settings", function () {
 
     cy.get('[data-test="room-settings-save-button"]').click();
 
+    cy.wait("@roomSettingsSaveRequest");
+
     // Check that error messages are set
     cy.get('[data-test="room-setting-access_code"]').should(
       "include.text",
@@ -1644,6 +1678,40 @@ describe("Rooms view settings", function () {
       "api/v1/rooms/abc-def-123",
       "settings",
     );
+
+    // Reload room page
+    cy.interceptRoomViewRequests();
+    cy.reload();
+
+    cy.get("#tab-settings").click();
+
+    cy.wait("@roomSettingsRequest");
+
+    // Check with 404 error (room not found)
+    cy.interceptRoomIndexRequests();
+
+    cy.intercept("PUT", "api/v1/rooms/abc-def-123", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "room",
+        ids: ["abc-def-123"],
+      },
+    }).as("roomSettingsSaveRequest");
+
+    cy.get('[data-test="room-settings-save-button"]').click();
+
+    cy.wait("@roomSettingsSaveRequest");
+
+    // Check that redirect to room index page worked
+    cy.url()
+      .should("include", "/rooms")
+      .and("not.include", "rooms/abc-def-123");
+
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
   });
 
   it("delete room", function () {
@@ -1714,8 +1782,15 @@ describe("Rooms view settings", function () {
     cy.get("[data-test=room-delete-dialog]").should("be.visible");
 
     // Check with 404 error
+    cy.interceptRoomIndexRequests();
+
     cy.intercept("DELETE", "api/v1/rooms/abc-def-123", {
       statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "room",
+        ids: ["abc-def-123"],
+      },
     }).as("roomDeleteRequest");
 
     cy.get("[data-test=room-delete-dialog]")
@@ -1725,12 +1800,24 @@ describe("Rooms view settings", function () {
 
     cy.wait("@roomDeleteRequest");
 
+    // Check that redirect to room index page worked
+    cy.url()
+      .should("include", "/rooms")
+      .and("not.include", "rooms/abc-def-123");
+
     cy.checkToastMessage([
-      "app.flash.server_error.empty_message",
-      'app.flash.server_error.error_code_{"statusCode":404}',
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
     ]);
 
-    // Check that modal stays open
+    // Reload room page
+    cy.visit("/rooms/abc-def-123#tab=settings");
+
+    cy.wait("@roomSettingsRequest");
+
+    // Open delete dialog again
+    cy.get('[data-test="room-delete-button"]').click();
+
     cy.get("[data-test=room-delete-dialog]").should("be.visible");
 
     // Check with 500 error
@@ -2257,5 +2344,41 @@ describe("Rooms view settings", function () {
       "api/v1/rooms/abc-def-123/transfer",
       "settings",
     );
+
+    // Reload room page
+    cy.interceptRoomViewRequests();
+    cy.reload();
+
+    cy.get("#tab-settings").click();
+
+    cy.wait("@roomSettingsRequest");
+
+    // Check with 404 error (room not found)
+    cy.interceptRoomIndexRequests();
+
+    cy.intercept("POST", "api/v1/rooms/abc-def-123/transfer", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "room",
+        ids: ["abc-def-123"],
+      },
+    }).as("transferOwnershipRequest");
+
+    cy.get('[data-test="room-transfer-ownership-button"]').click();
+    cy.get('[data-test="room-transfer-ownership-dialog"]').should("be.visible");
+    cy.get('[data-test="dialog-continue-button"]').click();
+
+    cy.wait("@transferOwnershipRequest");
+
+    // Check that redirect to room index page worked and error message is shown
+    cy.url()
+      .should("include", "/rooms")
+      .and("not.include", "rooms/abc-def-123");
+
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
   });
 });
diff --git a/tests/Frontend/e2e/RoomsViewStreaming.cy.js b/tests/Frontend/e2e/RoomsViewStreaming.cy.js
index ee3d562e5..5a7a80169 100644
--- a/tests/Frontend/e2e/RoomsViewStreaming.cy.js
+++ b/tests/Frontend/e2e/RoomsViewStreaming.cy.js
@@ -786,5 +786,30 @@ describe("Rooms view streaming", function () {
       "contain",
       "rooms.streaming.no_running_meeting",
     );
+
+    // Check 404 error on reload (room not found)
+    cy.interceptRoomIndexRequests();
+
+    cy.intercept("GET", "api/v1/rooms/abc-def-123/streaming/status", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "room",
+        ids: ["abc-def-123"],
+      },
+    }).as("roomStreamingStatus");
+
+    cy.get('[data-test="streaming-reload-button"]').click();
+    cy.wait("@roomStreamingStatus");
+
+    // Check that redirect to room index page worked and error message is shown
+    cy.url()
+      .should("include", "/rooms")
+      .and("not.include", "rooms/abc-def-123");
+
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
   });
 });
diff --git a/tests/Frontend/e2e/RoomsViewStreamingConfigActions.cy.js b/tests/Frontend/e2e/RoomsViewStreamingConfigActions.cy.js
index a24011106..a92235a73 100644
--- a/tests/Frontend/e2e/RoomsViewStreamingConfigActions.cy.js
+++ b/tests/Frontend/e2e/RoomsViewStreamingConfigActions.cy.js
@@ -277,6 +277,33 @@ describe("Rooms view streaming config actions", function () {
         // Close dialog
         cy.get('[data-test="dialog-cancel-button"]').click();
       });
+
+    // Check with 404 error (room not found)
+    cy.interceptRoomIndexRequests();
+
+    cy.intercept("GET", "api/v1/rooms/abc-def-123/streaming/config", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "room",
+        ids: ["abc-def-123"],
+      },
+    }).as("roomStreamingConfig");
+
+    cy.get('[data-test="streaming-config-button"]').should("be.visible");
+    cy.get('[data-test="streaming-config-button"]').click();
+
+    cy.wait("@roomStreamingConfig");
+
+    // Check that redirect worked and error message is shown
+    cy.url()
+      .should("include", "/rooms")
+      .and("not.include", "rooms/abc-def-123");
+
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
   });
 
   it("edit settings", function () {
@@ -598,6 +625,39 @@ describe("Rooms view streaming config actions", function () {
         // Close dialog
         cy.get('[data-test="dialog-cancel-button"]').click();
       });
+
+    // Check with 404 error (room not found)
+    cy.interceptRoomIndexRequests();
+
+    cy.intercept("POST", "api/v1/rooms/abc-def-123/streaming/config", {
+      statusCode: 404,
+      body: {
+        message: "model_not_found",
+        model: "room",
+        ids: ["abc-def-123"],
+      },
+    }).as("saveConfigRequest");
+
+    cy.get('[data-test="streaming-config-button"]').click();
+    cy.get('[data-test="room-streaming-config-dialog"]')
+      .should("be.visible")
+      .within(() => {
+        cy.get('[data-test="dialog-save-button"]')
+          .should("include.text", "app.save")
+          .click();
+      });
+
+    cy.wait("@saveConfigRequest");
+
+    // Check that redirect worked and error message is shown
+    cy.url()
+      .should("include", "/rooms")
+      .and("not.include", "rooms/abc-def-123");
+
+    cy.checkToastMessage([
+      'app.flash.model_not_found.title_{"model":"app.model.room"}',
+      'app.flash.model_not_found.details_{"ids":"abc-def-123"}',
+    ]);
   });
 
   it("view/edit settings with different permissions", function () {