Firefox 社群討論區

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 stopped working yesterday. When I open it, it immediately crashes. After multiple times of that I refreshed it as it asked. It then worked ok. However after closing it and coming back later, it again immediately crashes. I then tried uninstalling and reinstalling, but it still does not work.

I don't use Firefox daily, so not sure exactly when it last opened ok on my iMac (26.5.2). So I downloaded Version=153.0.1 BuildID=20260727124451, and tried again. When attempting to launch, the icon in the dock bounced a few times, then nothing. When repeated, it only bounces once.

Likely unrelated, but I had very recently upgraded my LuLu app (4.4.3) from Objective-See. It monitors outbound connections. But disabling the app changes nothing.

I'm not a MacOS guru. I expect there is an error in a log file somewhere that reveals the problem, but I don't know where to look.

Suggestions?

Anyone succeed with running Firefox in headless mode under Ubuntu?

I tried:

firefox --headless --safe-mode -P headless https://quan.hoabinh.vn

but got this error:

[12545] Sandbox: CanCreateUserNamespace() unshare(CLONE_NEWPID): EPERM

• • • You are running in headless mode.

[GFX1-]: RenderCompositorSWGL failed mapping default framebuffer, no dt

I installed Firefox as from "https://packages.mozilla.org/apt" repo.

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!

Can’t launch Firefox 3.5.19 on Linux Ubuntu When trying to run with:

./firefox

Terminal gives the following:

./firefox-bin: error while loading shared libraries: libdbus-glib-1.so.2: cannot open shared object file: No such file or directory

Today, I signed on to use my laptop, as usual, nothing different about how I sat down or anything, and I try to open Firefox and it flashes something on the screen, but I don't catch it as it immediately closes as well. It looked like a popup with a button, if that helps. I then try to open it again, realizing that I've got that bug, the one that causes browsers to open for a split-second and then close immediately, so I try to fix it how I fixed Opera GX before I stopped using that. Restarting? Nothing. Looking online for answers? Found some! I try starting it in Troubleshoot Mode, I can see down in my taskbar that Firefox is trying to open in Troubleshoot Mode but isn't. Okay, let's try something else, the Profile Manager. I use the Windows+R key to open the Run window and type in firefox.exe -p which according to a couple of websites, -This one included- should have opened the profile manager in a popup, but all I get is a flash of a window and nothing else. Then, I finally try uninstalling and reinstalling the app, upon reinstallation it asks if I want to keep my settings and whatnot, I say yes, problem persists. I uninstall and reinstall again, only this time declining the ability to keep my settings, the problem persists.

I'm extremely confused as to why nothing is working, and I don't want to have to reinstall Windows itself like I saw a comment on Reddit recommend, so if anybody has a slight idea of a solution, I'd be grateful, thank you in advance.

Edit: Just tried downloading and running Chrome, it worked for a second until it randomly closed, I know this isn't the support site for that browser, but I thought I'd mention that the "Not opening, just falshing for a millisecond" isn't just a Firefox thing for me.

Every so often for the past few days this "unfinished" program window has appeared on my pc on top of a normal Firefox window (see attached png). Does this have something to do with Firefox? I think the same thing appears when I first open Firefox, then it gets "filled in" and appears as a normal Firefox window. I am running Firefox 133.0.3 (64-bit) on Windows 10 Pro Version 22H2 build 19045.5247 Windows Feature Experience Pack 1000.19060.1000.0.

Hello! I am an avid user of firefox (especially with adblockers) on a windows 11 PC. Unfortunately, I have recently been experiencing an issue where when I attempt to open firefox, a window will open for a split second before instantly closing again. My PC is up to date, I have tried refreshing firefox and doing a clean install, but cannot seem to overcome the issue, or even open it in safe mode. Does anyone have any advice? Many thanks in advance!

Hello, When I went to launch Firefox after starting up my PC this morning, I was greeted with: "Your Firefox profile cannot be loaded. It may be missing or inaccessible".

I went right to the Mozilla forums and found the help page [https://support.mozilla.org/en-US/kb/how-run-firefox-when-profile-missing...] . In this article it detailed how I should go into my AppData, then Mozilla, then Firefox, and look to see where my profile.ini file is. My profile.ini file was there, alongside the installs.ini and a few other folders. I attempted also to launch the profile manager using run and the "firefox.exe -P" command, but I got the same profile error as when I tried launching the app. The help page then recommended deleting the profile.ini file and then launching Firefox to hopefully remake the default profiles.ini file and enable me to launch Firefox, so I attempted that. When I tried relaunching Firefox, the profiles.ini file did not re-appear in my Firefox folder.

I then tried deleting the Firefox folder itself, and relaunching Firefox. This resulted in it being remade, but with just 2 folders left: Crash Reports and Pending Pings. Obviously that's not ideal, so I right clicked the Firefox folder and used the Windows "Previous versions" feature to restore the Firefox folder to a backup of how it was this morning. I then re-tried launching and I still got the same missing profiles error message. I also briefly attempted manually making a new profiles.ini file with notepad, and pointing it towards my Profile withing my Profiles folder, but that still resulted in the same missing profiles error.

This is basically where I am at now. I have confirmed that I do in fact see my actual profile in my "C:\Users\****\AppData\Roaming\Mozilla\Firefox\Profiles" folder, and as far as I can tell my profiles.ini file correctly points towards it. I did another reset of my Firefox folder to a backup of where I was at this morning before attempting anything. I can confirm my Windows account (Admin, and only account on the computer) has full read and write access to all Folders and files within the Mozilla folder, although I will mention some of the files in the Firefox folder were marked with the "Read-Only" attribute (not sure if that matters, but I tried unchecking those and still no luck)

As far as I can tell I have thoroughly exhausted all the easily accessible tips on the internet for solving this, so I am wondering what to try next?

TLDR: Error: Your Firefox profile cannot be loaded. It may be missing or inaccessible" Already Attempted (And failed): -deleting and prompting a remake of the profiles.ini folder -using firefox.exe -P to launch Profile manager -deleting Firefox folder to prompt a remake of that -multiple uninstalls and reinstalls of Firefox -manually remaking profiles.ini file after it didn't come back after deletion

Will link images of (1) profiles.ini file. (2) Profiles folder.

Hi, We are using Horizon VDI terminal server. Firefox is installed on these servers. Some users get Firefox is already running but is not responding error. Ending Firefox via task manager does not work. I log off the user and have them log in again, but it does not work.

When I check, I see that the user's profile file cannot be created on any terminal server.

Is there a solution to this problem?

When I try and open Firefox, a window pops up for a millisecond before going off my screen, and firefox doesnt open. This is extremely irritating as i downloaded firefox since I also cant open chrome. Is there a fix to this, I have restarted my computer and have uninstalled and reinstalled firefox.

Thanks, Nathan

I'm trying to install Firefox on my work computer (ARM64 version), but when I do I'm getting the crash report window at the end of the installation process (multiple times in a row), if I try to open the browser (only once), and during the uninstallation process (also multiple times in a row). I've tried a clean reinstall multiple times, including deleting the folders from program files, %APPDATA%, and all registry entries I could find (HKEY_CURRENT_USER>>SOFTWARE, HKEY_LOCAL_MACHINE>>SOFTWARE, HKEY_LOCAL_MACHINE>>SOFTWARE>>WOW6432Node).

I've contacted IT and they don't seem to think anything pre-installed should be affecting this. I'm unable to get a crash ID as I'm unable to even start the browser - all I get is the Firefox crash reporter, immediately. Is someone able to help me figure out why I can't get this working?

Overnight firefox doesn't launch anymore.

I have firefox installed via Software Manager flatpak (official Mozilla version) but it doesn't launch anymore. Clicking launch does nothing. Version is 156.0

I tried to launch the program in safe mode via console but it straight up doesn't find it?

I would love to add troubleshooting info but I can't actually get to it. I assume an update broke something but no idea how to solve this, can I go to an earlier version?

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.

After the latest version was updated, Version 149.00.7, on my laptop, on 27 March 2026, the browser closed midway while I was working, and now I can no longer access Firefox.

When I click on the Icon to access I keep getting the following error message as per the attachment:

I have uninstalled Firefox and re-installed it THREE TIMES already', but I still get the same error as before, as per the screen print provided.

I have even tried to install Firefox with custom settings, but then in order to proceed with the installation the ONLY button to proceed was the "UPGRADE" option.

I am at my wits end because this is totally unacceptable and the updated version obviously DOES NOT WORK!!!

Your urgent attention and prompt action in sorting this out will be appreciated, thanks.

Hettie

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.

I need help with MacOS Sequoia 15.8.1 (24H32).

Since yesterday’s update to 15.8, Firefox and Thunderbird no longer work—regardless of the build or version. The system immediately terminates the apps with this message in the Apple error report:

System Integrity Protection: enabled Crashed Thread: 0 MainThread Dispatch queue: com.apple.main-thread Exception Type: EXC_GUARD (SIGKILL) Exception Codes: GUARD_TYPE_MACH_PORT Exception Codes: 0x0000000000000203, 0x0000000000000000 Termination Reason: Namespace GUARD, Code 2305843146652647939

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