Zen crashes when in the background on MacOS 15.7.4

[bricker152]

Preliminary Checks

• I have read and understood the important section above.
• I have searched existing issues and avoided creating duplicates.
• I am not filing an enhancement request.
• I have checked that this issue cannot be reproduced on Mozilla Firefox.
• I have checked that this issue can be reproduced once I removed all my Mods and Custom CSS.

What happened?

Quite often, but randomly, if I switch to other windows, when clicking back to Zen it crashes. Sometimes it crashes silently in the background, I only find out when I want to open it, and all the tabs are unloaded. It does save the state, but all the tabs are unloaded. It is hard to reproduce, I will try to gather as much data as I can when it happens. For now, I only have the report that MacOS gives when a program crashes and have pasted an excerpt of that below. I am not a programmer, so I don't know if that is of any help. It happens independent of installed addons or extensions, and which tabs are open does not seem to matter.

Expected behavior

Zen should stay open when in the background or minimized.

Actual behavior

Zen crashes when its window is not visible or it is minimized to the dock.

Steps to reproduce

Unknown. Sometimes it happens when the window is not minimized but just hidden by other windows, sometimes it happens when I minimize to the dock. Everytime the dot beside the icon in the dock dissapears and when clicking the icon Zen starts like it was closed. It does retain all of the tabs, because I have it set to reopen tabs when starting.

Screenshots and videos

No response

Version

1.19.7b (Firefox 149.0.2) (aarch64)

What platform are you seeing the problem on?

macOS - aarch64

What component is this issue related to?

Performance

Relevant log output if applicable

rocess:               zen [992]
Path:                  /Applications/Zen.app/Contents/MacOS/zen
Identifier:            app.zen-browser.zen
Version:               1.19.7b (126.4.7)
Code Type:             ARM-64 (Native)
Parent Process:        launchd [1]
User ID:               501

Date/Time:             2026-04-17 09:05:05.2189 +0200
OS Version:            macOS 15.7.4 (24G517)
Report Version:        12
Anonymous UUID:        CA8B1B1A-6E60-DB96-26A6-3B024B78C66B

Sleep/Wake UUID:       4952C1BD-4126-4DC9-9FA0-9A42E7E84C86

Time Awake Since Boot: 370000 seconds
Time Since Wake:       723 seconds

System Integrity Protection: enabled

Crashed Thread:        0  MainThread  Dispatch queue: com.apple.main-thread

Exception Type:        EXC_BAD_ACCESS (SIGSEGV)
Exception Codes:       KERN_INVALID_ADDRESS at 0x0065e5e5e5e5e5f0 -> 0x000065e5e5e5e5f0 (possible pointer authentication failure)
Exception Codes:       0x0000000000000001, 0x0065e5e5e5e5e5f0

Termination Reason:    Namespace SIGNAL, Code 11 Segmentation fault: 11
Terminating Process:   exc handler [992]

VM Region Info: 0x65e5e5e5e5f0 is not in any region.  
      REGION TYPE                    START - END         [ VSIZE] PRT/MAX SHRMOD  REGION DETAIL
      UNUSED SPACE AT START
--->  
      UNUSED SPACE AT END

Thread 0 Crashed:: MainThread Dispatch queue: com.apple.main-thread
0   libobjc.A.dylib               	       0x18cba9820 objc_msgSend + 32
1   XUL                           	       0x12b39650c 0x126ea4000 + 72295692
2   XUL                           	       0x1284ee200 0x126ea4000 + 23372288
3   XUL                           	       0x1284ee0a0 0x126ea4000 + 23371936
4   CoreFoundation                	       0x18d07b3bc __CFNOTIFICATIONCENTER_IS_CALLING_OUT_TO_AN_OBSERVER__ + 148
5   CoreFoundation                	       0x18d10aa78 ___CFXRegistrationPost_block_invoke + 92
6   CoreFoundation                	       0x18d10a9bc _CFXRegistrationPost + 436
7   CoreFoundation                	       0x18d04a808 _CFXNotificationPost + 740
8   Foundation                    	       0x18e604680 -[NSNotificationCenter postNotificationName:object:userInfo:] + 88
9   AppKit                        	       0x1910f2990 _NXShowKeyAndMain + 116
10  AppKit                        	       0x1910f0df0 -[NSApplication _handleActivatedEvent:] + 1368
11  AppKit                        	       0x191943498 -[NSApplication(NSEventRouting) sendEvent:] + 1836
12  XUL                           	       0x126ea8778 0x126ea4000 + 18296
13  AppKit                        	       0x19154242c -[NSApplication _handleEvent:] + 60
14  AppKit                        	       0x190f98c0c -[NSApplication run] + 520
15  XUL                           	       0x126ea86a4 0x126ea4000 + 18084
16  XUL                           	       0x1283c64d8 0x126ea4000 + 22160600
17  XUL                           	       0x12894e788 0x126ea4000 + 27961224
18  XUL                           	       0x128312d50 0x126ea4000 + 21425488
19  XUL                           	       0x1284d9f90 0x126ea4000 + 23289744
20  XUL                           	       0x1284d948c 0x126ea4000 + 23286924
21  zen                           	       0x104b70efc 0x104b70000 + 3836
22  dyld                          	       0x18cbfab98 start + 6076

[bricker152]

Zen just updated when I opened it again after crashing and it crashed again a few minutes later. I am pasting the report from MacOS for the latest crash, if it is any help.

Path:                  /Applications/Zen.app/Contents/MacOS/zen
Identifier:            app.zen-browser.zen
Version:               1.19.7b (126.4.7)
Code Type:             ARM-64 (Native)
Parent Process:        launchd [1]
User ID:               501

Date/Time:             2026-04-17 09:05:05.2189 +0200
OS Version:            macOS 15.7.4 (24G517)
Report Version:        12
Anonymous UUID:        CA8B1B1A-6E60-DB96-26A6-3B024B78C66B

Sleep/Wake UUID:       4952C1BD-4126-4DC9-9FA0-9A42E7E84C86

Time Awake Since Boot: 370000 seconds
Time Since Wake:       723 seconds

System Integrity Protection: enabled

Crashed Thread:        0  MainThread  Dispatch queue: com.apple.main-thread

Exception Type:        EXC_BAD_ACCESS (SIGSEGV)
Exception Codes:       KERN_INVALID_ADDRESS at 0x0065e5e5e5e5e5f0 -> 0x000065e5e5e5e5f0 (possible pointer authentication failure)
Exception Codes:       0x0000000000000001, 0x0065e5e5e5e5e5f0

Termination Reason:    Namespace SIGNAL, Code 11 Segmentation fault: 11
Terminating Process:   exc handler [992]

VM Region Info: 0x65e5e5e5e5f0 is not in any region.  
      REGION TYPE                    START - END         [ VSIZE] PRT/MAX SHRMOD  REGION DETAIL
      UNUSED SPACE AT START
--->  
      UNUSED SPACE AT END

Thread 0 Crashed:: MainThread Dispatch queue: com.apple.main-thread
0   libobjc.A.dylib               	       0x18cba9820 objc_msgSend + 32
1   XUL                           	       0x12b39650c 0x126ea4000 + 72295692
2   XUL                           	       0x1284ee200 0x126ea4000 + 23372288
3   XUL                           	       0x1284ee0a0 0x126ea4000 + 23371936
4   CoreFoundation                	       0x18d07b3bc __CFNOTIFICATIONCENTER_IS_CALLING_OUT_TO_AN_OBSERVER__ + 148
5   CoreFoundation                	       0x18d10aa78 ___CFXRegistrationPost_block_invoke + 92
6   CoreFoundation                	       0x18d10a9bc _CFXRegistrationPost + 436
7   CoreFoundation                	       0x18d04a808 _CFXNotificationPost + 740
8   Foundation                    	       0x18e604680 -[NSNotificationCenter postNotificationName:object:userInfo:] + 88
9   AppKit                        	       0x1910f2990 _NXShowKeyAndMain + 116
10  AppKit                        	       0x1910f0df0 -[NSApplication _handleActivatedEvent:] + 1368
11  AppKit                        	       0x191943498 -[NSApplication(NSEventRouting) sendEvent:] + 1836
12  XUL                           	       0x126ea8778 0x126ea4000 + 18296
13  AppKit                        	       0x19154242c -[NSApplication _handleEvent:] + 60
14  AppKit                        	       0x190f98c0c -[NSApplication run] + 520
15  XUL                           	       0x126ea86a4 0x126ea4000 + 18084
16  XUL                           	       0x1283c64d8 0x126ea4000 + 22160600
17  XUL                           	       0x12894e788 0x126ea4000 + 27961224
18  XUL                           	       0x128312d50 0x126ea4000 + 21425488
19  XUL                           	       0x1284d9f90 0x126ea4000 + 23289744
20  XUL                           	       0x1284d948c 0x126ea4000 + 23286924
21  zen                           	       0x104b70efc 0x104b70000 + 3836
22  dyld                          	       0x18cbfab98 start + 6076

[mr-cheffy]

Could you please try opening up zen in troubleshooting mode? (about:support) and see if it still crashes?

[bricker152]

I've been running it in troubleshooting mode for about an hour and so far it seems stable. I did disable all extensions before (a while back, when this started happening), but it still crashed sometimes. But in the normal mode it also is stable for a while, then I get a few random crashes and it can be fine for a few days, then it starts crashing again. It is really unpredictable and I can't figure out what triggers it. I will use it in troubleshooting mode for a while, and report back if/when it crashes again.

[bricker152]

I just got a crash again in troubleshooting mode. Let me know if there are any more logs I can send, so it gives you a better idea of what is happening.

Translated Report (Full Report Below)
-------------------------------------

Process:               zen [58116]
Path:                  /Applications/Zen.app/Contents/MacOS/zen
Identifier:            app.zen-browser.zen
Version:               1.19.8b (126.4.8)
Code Type:             ARM-64 (Native)
Parent Process:        launchd [1]
User ID:               501

Date/Time:             2026-04-17 12:11:14.4729 +0200
OS Version:            macOS 15.7.4 (24G517)
Report Version:        12
Anonymous UUID:        CA8B1B1A-6E60-DB96-26A6-3B024B78C66B

Sleep/Wake UUID:       DC30674B-92E0-4B20-9ED9-8D9F7DB480F5

Time Awake Since Boot: 380000 seconds
Time Since Wake:       7221 seconds

System Integrity Protection: enabled

Crashed Thread:        0  MainThread  Dispatch queue: com.apple.main-thread

Exception Type:        EXC_BAD_ACCESS (SIGSEGV)
Exception Codes:       KERN_INVALID_ADDRESS at 0x0065e5e5e5e5e5f0 -> 0x000065e5e5e5e5f0 (possible pointer authentication failure)
Exception Codes:       0x0000000000000001, 0x0065e5e5e5e5e5f0

Termination Reason:    Namespace SIGNAL, Code 11 Segmentation fault: 11
Terminating Process:   exc handler [58116]

VM Region Info: 0x65e5e5e5e5f0 is not in any region.  
      REGION TYPE                    START - END         [ VSIZE] PRT/MAX SHRMOD  REGION DETAIL
      UNUSED SPACE AT START
--->  
      UNUSED SPACE AT END

Thread 0 Crashed:: MainThread Dispatch queue: com.apple.main-thread
0   libobjc.A.dylib               	       0x18cba9820 objc_msgSend + 32
1   XUL                           	       0x1484fb524 0x144000000 + 72332580
2   XUL                           	       0x14565d9c4 0x144000000 + 23452100
3   XUL                           	       0x14565d864 0x144000000 + 23451748
4   CoreFoundation                	       0x18d07b3bc __CFNOTIFICATIONCENTER_IS_CALLING_OUT_TO_AN_OBSERVER__ + 148
5   CoreFoundation                	       0x18d10aa78 ___CFXRegistrationPost_block_invoke + 92
6   CoreFoundation                	       0x18d10a9bc _CFXRegistrationPost + 436
7   CoreFoundation                	       0x18d04a808 _CFXNotificationPost + 740
8   Foundation                    	       0x18e604680 -[NSNotificationCenter postNotificationName:object:userInfo:] + 88
9   AppKit                        	       0x1910f2990 _NXShowKeyAndMain + 116
10  AppKit                        	       0x1910f0df0 -[NSApplication _handleActivatedEvent:] + 1368
11  AppKit                        	       0x191943498 -[NSApplication(NSEventRouting) sendEvent:] + 1836
12  XUL                           	       0x14400478c 0x144000000 + 18316
13  AppKit                        	       0x19154242c -[NSApplication _handleEvent:] + 60
14  AppKit                        	       0x190f98c0c -[NSApplication run] + 520
15  XUL                           	       0x1440042fc 0x144000000 + 17148
16  XUL                           	       0x1455246c8 0x144000000 + 22169288
17  XUL                           	       0x145aa29b0 0x144000000 + 27929008
18  XUL                           	       0x1450056b4 0x144000000 + 16799412
19  XUL                           	       0x14564d180 0x144000000 + 23384448
20  XUL                           	       0x14564c67c 0x144000000 + 23381628
21  zen                           	       0x102914efc 0x102914000 + 3836
22  dyld                          	       0x18cbfab98 start + 6076

[mr-cheffy]

Do you have any mods, addons, etc? Do you have "sine" installed?

[bricker152]

The only mod I have installed is No Top Sites (v1.1.0), I have a few extensions; Ublock Origin, SponsorBlock, TWP - translate web pages, Privacy badger, Tab Wrangler. But they all got disabled in troubleshooting mode.
I do not have sine installed. The only mod that modifies anything related to theming is Zen Colored Picker (v2.0.1), but I disabled it a long time ago (granted, I didn't remove it yet).