Firefox Community Forum

As title: after running updates, Firefox consistently crashes when launching.

To give more concrete details:

-Running on Linux, specifically KDE Fedora 42. Firefox was updated to 142 from 141, alongside various other updates. -When launching Firefox from any source (directly, through a link, through the terminal etc.), the only window that appears is the crash reporter. -This issue occurs when launching in safe mode. Removing and reinstalling Firefox, including deleting the entire .mozilla folder in Home at the same time does not resolve the issue. I am unable to test rolling Firefox back to 141. -When attempting to launch from the terminal (safe mode or otherwise), the following is output (personal info redacted):

restorecon: SELinux: Could not get canonical path for /home/[username]/.mozilla/firefox/*/gmp-widevinecdm/* restorecon: No such file or directory.

/usr/include/c++/15/array:210: constexpr std::array<_Tp, _Nm>::value_type& std::array<_Tp, _Nm>::operator[](size_type) [with _Tp = HeaderBarButtonType; long unsigned int _Nm = 3; reference = HeaderBarButtonType&; size_type = long unsigned int]: Assertion '__n < this->size()' failed.

Redirecting call to abort() to mozalloc_abort

[ExceptionHandler generates a minidump etc.]

Gtk-Message: [timestamp]: Failed to load module "appmenu-gtk-module"

(I would note that to the best of my knowledge I had not included a plugin for decoding widevine in my Firefox setup, and certainly the Firefox 141 instance on the device being used to write this post (same OS) does not include it) -The crash files in the .mozilla folder, meanwhile, consistently list a segfault at address 0x0.

Any advice on diagnosing/solving this issue would be greatly appreciated. Let me know if there's any other information that would be helpful.

If it would be more appropriate, I could report this through Mozilla's bugzilla instance, but given the issue seems to be very niche (Fedora's ABRT shows a total of 5 unique affected users in the last few days) I am unsure whether flagging this there would be appropriate.

When I try to run firefox 141.0 (Linux x64) I get:

libxul.so: undefined symbol: gdk_wayland_device_get_wl_seat Couldn't load XPCOM.

Is there a way to fix this?

I'm using Slackware 14.2.

Please tell me how to resolve this issue. The 3 reports I have submitted from the crash window are:

Crash ID: ⁨bp-4107d3db-4280-445b-a0cd-e96400251020⁩ [10/20/2025 2:43 PM (Pacific)] Crash ID: ⁨bp-b5e0bbf3-d4f6-4b2a-898a-f56960251020⁩ [10/20/2025 2:40 PM (Pacific)] Crash ID: ⁨bp-975fcb26-5886-492f-8253-e37820251020⁩ [10/20/2025 2:39 PM (Pacific)]

Mozilla Firefox is very slow and even difficult to open.....I am using this browser since ten years and never had any problem....Please do the needful at your earliest...Thank a lot....RASIK MER

Mozilla Firefox is very slow and even difficult to open.....I am using this browser since ten years and never had any problem....Please do the needful at your earliest...Thank a lot....RASIK MER

Hi,

I am using OS MX-25 Linux and after importing my previous FF profile from an earlier version of MX everything in Firefox 145.0 was fine: my bookmarks and extensions all loaded and everything was tickety-boo. However, after I attempted to relaunch FF I got the following message:

Your Firefox profile cannot be loaded. It may be missing or inaccessible.

I have tried numerous times to launch FF but just keep getting this message.

Eventually it launched, but after a while pages refused to load properly and so I closed it down. Since then, I have been unable to get FF to open.

Any help would be greatly appreciated.

My Surface Laptop 7 w/ SnapDragon Elite's Firefox installation started crashing this morning immediately after rebooting to complete some Windows updates. I have attempted starting Firefox in Maintenance mode, Uninstalled and reinstalled and I still get the crash reporter. Refreshing Firefox at the uninstall process does not fix it.

I'm running Windows 11 Enterprise edition, fully patched w/ Firefox 146.0.

The 4 Windows updates that were installed:

Uninstalled KB5072033 Uninstalled KB5070311 Cannot be uninstalled KB5072641 Cannot be uninstalled KB5071142

Still didn't fix the problem.

These are the recent crash reports:

Crash ID: ⁨bp-8ec5b63c-4408-437c-b9bb-f4d5b0251213⁩ Crash ID: ⁨bp-ce396463-0a75-46b6-8131-33cce0251213⁩ Crash ID: ⁨bp-ea0b59dd-1cee-48da-957e-949120251213⁩ Crash ID: ⁨bp-f9342e01-1a55-4387-af6d-3b8ef0251213⁩

Any help is appreciated!

Firefox 146.0.1 crashes every time upon launch (basically fails to launch), even in troubleshooting mode, with exception code 0xc0000005. Prior to today, it was working fine. Windows does not show any updates made over the last couple of days. I am on Windows 11 25H2, and I'm current with updates. Chrome works. Edge works. I logged on to the same computer as a different user (different profile folder in the user AppData folder) and Firefox still does not work. I tried to refresh Firefox and that did not resolve the issue. I tried to uninstall and reinstall Firefox and that did not resolve the issue. I tried to run DISM and SCANNOW and that did not resolve the issue. No issues are detected with a virus scan. I am stumped - please help!

Actually this is just the only route I could figure out to your page where I had PREVIOUSLY asked this question and was checking back in to see whether 'the Community' had given me an answer yet. I'm no doubt IMPATIENT since my bank told me I need you, not Google and Microsoft Edge , who I both HATE for coming on to MY laptop, asking for more information sharing and basically DEMANDING I follow their marketing instructions since they had somehow REMOVED the X at the top right corner and simultaneously BLOCKED my access to and use of my OWN laptop, so that each time I have NO OPTION but to turn off the power on my laptop, to "reboot" as they once said. If even a basic, ancient telephone can be HUNG UP on scammers.....forgive me. I REALLY want to use your search engine, as WELL as your site. Please advise.

Through extensive troubleshooting, I am unable to get firefox to open at all.

I've done a full uninstall, cleaned all user directories, program files / x86, program data, appdata roaming and local, etc. I used the Microsoft uninstaller and even Revo Uninstaller to remove everything related to Firefox, did a restart and reinstall of the latest one and it still won't launch.

Firefox was previously working until a reboot occurred and now it won't launch.

Firefox 32 bit seems to work when installed, and running Firefox as an admin previously worked but no it no longer does.

I looked at the following articles: - https://support.mozilla.org/en-US/kb/firefox-wont-start-find-solutions - https://support.mozilla.org/en-US/kb/profile-manager-create-remove-switch-firefox-profiles - https://support.mozilla.org/en-US/kb/profile-manager-create-remove-switch-firefox-profiles#w_start-the-profile-manager-when-firefox-is-closed

There's no malware on this machine (business EDR on it, even disabled it as a test and it still didn't open).

I was able to launch the profile manager but now I am unable to as the processes launch in task manager and then within 5 seconds they close.

Firefox is not running in the background for any user (I'm the only one logged in after a reboot as well)

I'm unable to open in troubleshoot mode either. Tried run as and admin cmd "C:\Program Files\Mozilla Firefox\firefox.exe" -safe-mode

Ran SFC / scannow / DISM restore health commands as well and both came back fine / no integrity violations

Hi, after clicking FF icon, I got nothing. Profile manager (firefox.exe -P) does not start. In event viewer there is log: Name of the application causing the error: firefox.exe, version: 147.0.0.11, timestamp: 0x695c3722 Name of the module causing the error: unknown, version: 0.0.0.0, timestamp: 0x00000000 Exception code: 0xc0000005 Fault offset: 0x00007ffc561c6160 Faulting process ID: 0x4A54 Startup time of the application causing the error: 0x1DC85EE68CB3BAD Faulting application path: C:\Program Files\Mozilla Firefox\firefox.exe Faulting module path: unknown Report Id: e599c553-d77c-4b73-a863-1ccaa8d3bd4c Faulting full package name: Faulting relative application ID for package:

Last time deleting profile was helpfull, today nothing helps... Reinstall - the same... Any ideas?