Firefox Community Forum

Application error: a client-side exception has occurred while loading (see the browser console for more information).

where is the browser console? how do i fix it never had an issue with until the last two days?

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?

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

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!

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!

Greetings Ya'll,

I have to apologize if this is a double post, but I came back to the forum, & wanted to see if there were any responses, but i could only find my post listed under "My Profile"/"My Questions".

My original post was made Dec. 19-2025

=======================================

Early this morning as I went to use the Firefox browser, on My Desktop, I got an update, & then firefox opened, somewhat.

The homepage did not fill in with favorites, suggestions, etc, and in fact all that did load was the Search bar, but not one of my usual website buttons. The "edit", "help", etc. buttons at the upper left hand corner did load, but that is all. Not one of the buttons work, nor can I close out the Firefox page, by tapping the "X" in the upper right hand corner.

The only way that I could close out the "Firefox Page" was by going through the "Control/Alt/Delete" & then "Signing Out", which would initiate a "Re-start". Once I signed in, I could return to the Desktop, where everything works.

I use Firefox as my Browser on my Android phone, & at this moment, I've not had any problems using Firefox on my Cell Phone.

The only way that I could get to the Mozilla Website was by using the Microsoft Edge Browser, which is not giving me any problems as far as accessing the Internet!

How can I correct this problem, & go back to the Firefox Browser?

Firefox is already running old Firefox must be closed. I have tried everything in the help menu. delete parent.lock , restarting etc. nothing is working. I can create new profile but i cant find any toolbar, bookmarks etc please help

I’m suddenly unable to open Mozilla Firefox at all on my Windows 11 Pro (version 25H2) Surface Laptop. The browser never launches - every attempt immediately crashes and opens the Firefox Crash Reporter.

I tried uninstalling and reinstalling a fresh copy of Firefox (and removing the old application files, though the original Firefox program folder has 13 .tmp files inside a “tobedeleted” folder that I can’t delete), but the issue persists. When I try to install or uninstall Firefox, I get the same behavior: Firefox never opens, and I end up with multiple instances of the Crash Reporter popping up instantly.

Tried renaming firefox.exe as well to no avail. Chrome and Edge are working fine.

since 3 days, after initiation of the Firefox the empty page appears with order to close firefox. A have reinstalled the new version several times withour anu change in the program behaviour

As the title says Firefox has stopped working for Mac a few days ago after the update. all I get when I open it is a blank grey box. My software is up to date and I have uninstalled and reinstalled Firefox multiple times, nothing worked. is there any way to fix this other than waiting for Firefox to update again? I just want to bring this to Firefox's attention so it can be fixed, I like Firefox it's my go-to browser to use.

A few days ago (December 17th or so), Firefox just up and stopped loading altogether. I’m trying everything I can find, but to no avail. The internet itself is working fine. This is the message I’m getting (see attached).

I’m getting desperate, I can only do so much on my phone!

Thanks, Alsie

I try hard to use firefox in headless mode for a python selenium project in freebsd. But firefox complains about GPUs and the absense of a X-Server, but this is a headless mode and crashes with a segmentation fault. Why does it want a GPU and X-Server in headless mode? Does not make sense.

The output when i try to start is : " firefox --headless

• • • You are running in headless mode.

Crash Annotation GraphicsCriticalError: |[0][GFX1-]: glxtest: Unable to open a connection to the X server (t=0.117314) [GFX1-]: glxtest: Unable to open a connection to the X server Crash Annotation GraphicsCriticalError: |[0][GFX1-]: glxtest: Unable to open a connection to the X server (t=0.117314) |[1][GFX1-]: No GPUs detected via PCI (t=0.117314) [GFX1-]: No GPUs detected via PCI

Crash Annotation GraphicsCriticalError: |[0][GFX1-]: glxtest: Unable to open a connection to the X server (t=0.117314) |[1][GFX1-]: No GPUs detected via PCI (t=0.117314) |[2][GFX1-]: Failed to initialize shared font list, falling back to in-process list. (t=0.118314) [GFX1-]: Failed to initialize shared font list, falling back to in-process list. Segmentation fault (core dumped) firefox --headless "

Can anyone help me? Best regards Josef

Whenever I try to open firefox it automatically opens google chrome, I haven’t used chrome for over a year and i’ve set firefox as my default app for everything. I double checked the shortcut to make sure it’s going to the right place and it is. and i’ve tried deleting Chrome via Revo Uninstaller but the issue persists.

this wasn’t happening 5 minutes ago and i can’t exactly think of a reason for the change.

Every time i would open the app, it would crash immediately. I uninstalled and reinstalled, had the same issue. Recently updated to Win11. Reported each time but can't get into the app so don't know what the error is.

When I open Firefox in Windows 11 a small window appears that reads, "Firefox Couldn't load XPCOM. I have not found any solutions to stop this that work. Will Mozilla fix this?