Firefox Community Forum

In my org - ever since the release of Firefox 146 - each time an update is rolled out on a WIndows 11 endpoint - Firefox is no longer able to launch.

This is resolved by uninstalling and reinstalling the client. We've had no issues with the ESR release in my testing.

What changed? Anyone else experiencing this?

I had our security team take a look at the antivirus - they've confirmed we aren't blocking Firefox and they did not see any block reports.

No relevant policy changes have gone through around the time of the incident. Initially I suspected users were installing Firefox ESR from the Company Portal alongside the standard release - but confirmed this is not the case. Also ruled out browser extensions - error persisted across a config without any extensions.

Please let me know if there is troubleshooting info I can collect. I included info from my own browser, but I reinstalled on the 27th and it has been working since. However, it has broke specifically on the days new releases have come out.

Thank you for any suggestions!

firefox doesnt start and gives me this error If i uninstall the have a fresh, install, everything will work normally until i restart my pc

AvailablePageFile: 13664788480 AvailablePhysicalMemory: 20233519104 AvailableVirtualMemory: 138533665595392 BackgroundTaskMode: 0 BuildID: 20260116091309 CPUMicrocodeVersion: 0xa50000d CrashTime: 1769253421 HeadlessMode: 0 InstallTime: 1768730212 LastStartupWasCrash: 1 ModuleSignatureInfo: {"Mozilla Corporation":["firefox.exe","xul.dll","gkcodecs.dll","nss3.dll","mozglue.dll","lgpllibs.dll"],"Microsoft Windows Software Compatibility Publisher":["msvcp140.dll","VCRUNTIME140.dll","VCRUNTIME140_1.dll"],"Microsoft Windows":["wsock32.dll","DWrite.dll","textinputframework.dll","dbgcore.dll","dbghelp.dll","version.dll","CoreUIComponents.dll","CoreMessaging.dll","ktmw32.dll","WinTypes.dll","propsys.dll","uxtheme.dll","dwmapi.dll","kernel.appcore.dll","windows.storage.dll","ntmarta.dll","CRYPTBASE.dll","wldp.dll","ntasn1.dll","ncrypt.dll","msasn1.dll","profapi.dll","KERNELBASE.dll","ucrtbase.dll","bcryptPrimitives.dll","gdi32full.dll","win32u.dll","bcrypt.dll","msvcp_win.dll","wintrust.dll","cfgmgr32.dll","crypt32.dll","user32.dll","oleaut32.dll","shlwapi.dll","advapi32.dll","msvcrt.dll","imm32.dll","ole32.dll","rpcrt4.dll","shell32.dll","kernel32.dll","SHCore.dll","ws2_32.dll","gdi32.dll","sechost.dll","psapi.dll","combase.dll","msctf.dll","ntdll.dll"]} ProductID: {ec8030f7-c20a-464f-9b0e-13a3a9e97384} ProductName: Firefox ReleaseChannel: release SafeMode: 0 SecondsSinceLastCrash: 899 StartupCacheValid: 0 StartupCrash: 1 StartupTime: 1769253421 SubmittedFrom: Client SystemMemoryUsePercentage: 40 Throttleable: 1 TotalPageFile: 37688152064 TotalPhysicalMemory: 34198491136 TotalVirtualMemory: 140737488224256 UptimeTS: .1135774 Vendor: Mozilla Version: 147.0.1 Ce rapport contient également des informations techniques sur l’état de l’application lors du plantage.

Dell installed a command update and immediately afterwards, Firefox would no longer open, either from the taskbar icon or from settings/apps. I just get a couple of seconds of the blue cycle icon and then nothing, no error message, just nothing. I did download/install repeatedly but I don't get beyond the download screen - as soon as it's 100% downloaded, that's it, no welcome window, nothing. Thanks

Hello I had Mozilla Firefox as my default browser on my Mac laptop

I got a message this morning that Firefox could not open

I tried several times but no luck

I read through some of the online HELP sites and deleted the Firefox app and reloaded it

I also cleared the browsing history on SAFARI and CHROME although I couldn't see why that would work

Still not able to get FIREFOX to open

After upgrading to version 144 in Windows 11, the portable version of firefox stopped opening, the splash screen appears and shuts down. If you run firefox.exe, it works, but the portable program itself crashes and won't start. There is nothing in the logs, antivirus is off, windows security is turned off. How to fix this?

I have made multiple efforts to download Firefox onto a recently acquired laptop but it doesn't launch.

The laptop is a Dell Latitude 5520 running Windows 11 Pro.

I have on several occasions downloaded Firefox.exe (version 146.0.1.763), double clicked to start it, clicked to approve that the app can make changes and watched as the installation graphic fills and I get confirmation that installation has completed. Then nothing.

I have uninstalled the app and started again. No change.

The app appears in the list of apps (I have successfully made Firefox the default browser) but I don't know how to launch it.

I would be grateful if someone could provide the solution!

M

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

On my pc, Mozilla Firefox continuously loops the error message, “Firefox is already running, but is not responding. The old Firefox process must be closed to open a new window.” It then proceeds to close and loop this error. I have uninstalled and reinstalled multiple times, as well as did a “refresh” in deleting all my extensions and addons upon the new installation. Please advise. Thank you.

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?