Firefox コミュニティフォーラム

Hi, The browser suddenly closed, and I can't open it since then. I searched for what to do but couldn't find anything helpful. I tried reinstalling Firefox, but it still doesn't work. I don't know it is a helpful information, but the other browsers (like Chrome and Opera) also don't open.

I am having Firefox crash on startup much like Firefox Desktop crashing on startup, initially in version 140, but I have downgraded to version 139 in my troubleshooting and I'm getting the same symptom.

It is frustrating that this does not seem to leave any records in the Windows event log or the Firefox crash reports, and that the fact that there's a known issue of this severity is rather hard to find.

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.

Firefox is my default browser. I few days ago, it failed to open, and continues to do so. When I click on the icon, I get the blue spinning circle for a few seconds, then nothing. I have tried to refresh and reinstall, but nothing worked.

Firefox keeps crashing, or better doesnt even open. In Task Maneger on my Windows 11 System I didnt even see the task preformed. So I tried to uninstall Firefox and reinstall Firefox, still the same Problem. I tried to refresh Firefox but it was no use. Sometimes for a brief moment of time a small window opens with the Firefox logo, for two seconds I can read the word Firefox Troubleshoot but it closes instantly. I need Firefox as my Browser and would like to have it back in use as soon as possible. Thank you for your help LH

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

PLEASE READ UNTIL THE END So, a few months ago I reinstalled Windows on my laptop because I had some bugs. After the OOBE was completed, I set it up and installed Chrome. However, when I tried to log in, the app suddenly force closed and could no longer be opened. So, I switched to Firefox. Everything was running fine. But now (06/26/2025), while I was using Firefox, it suddenly force closed (this is the first time it has force closed on me). I clicked twice on the desktop but it also didn't work, I'm confused about what to do, I absolutely don't want to use Microsoft Edge. When I tried to spam the Firefox icon on the taskbar while opening the task manager, crashhelper.exe suddenly appeared many times, I tried to delete those exe files but it had no effect, so I restored them back to their directory. I'm really confused whether my laptop is broken or if there's a bug in the Windows software? So that's it and thank you.

export GDK_BACKEND=x11 MOZ_ENABLE_WAYLAND=0 MOZ_DISABLE_WAYLAND=1; /mnt/bootdrive/firefox3/firefox/firefox -P tx1p72s0.dev-edition-default XPCOMGlueLoad error for file /mnt/bootdrive/firefox3/firefox/libxul.so: /mnt/bootdrive/firefox3/firefox/libxul.so: undefined symbol: gdk_wayland_device_get_wl_seat Couldn't load XPCOM.

Has support for X11 been removed?

Ive uninstalled it multiple times, done just about everything suggested online, and even got it working for a bit off the Microsoft store. But for some reason, my desktop Firefox will not open at all.

Firefox has begun to instantly crash after opening. This occurs constantly, even though fresh installs, even if I run as administrator. It is the only application doing this, which is beyond weird. It seems to have begun happening after I opened a notepad file. Which seems ridiculous to me but that's when it initially crashed. If more information is required, please let me know, but I cannot even access say, crash logs.

Firefox was working perfectly up until this morning and I'm pretty sure there wasn't a new update today. But now when I open the app a new window will briefly pop up for a fraction of a second and then disappear. Unfortunately this prevents me from accessing troubleshoot mode or crash reports so i can't provide much information on specifics.

I followed the steps here: https://support.mozilla.org/en-US/kb/firefox-keeps-crashing-startup and they haven't worked so far. I tried a clean install and restarting my computer multiple times, but no dice. There also don't seem to be any compatibility issues with the most recent version in the release notes.

- Had 3 windows open with numerous tabs and tab groups - Firefox sync was enabled, as well as a 2-3 plugins AFAIK - Version installed is latest as of this writing 139.0.4 - Initial crash caused by opening and quickly closing (IF that succeeded before crash) a onedrive share link - Cannot start firefox any more, also not in safe mode - the only thing that works is launching it with a fresh profile.

The report ID is bp-a8c824fc-a7fb-4290-a72b-b63160250620

Ideally I can resolve this without needing to refresh or start over with a new profile

I am still using Win 7 but converting to Win 11. The most recent "patch Tuesday" update from MS killed Office 2016. Since then Fire Fox will occasionally pop up the "Couldn't load XPCOM." (no file extension) warning. It may do this when opened but not always. Can also occur in the midst of a session.

Program seems to be working correctly but some of my pinned locations disappeared when this started. New locations are retained between sessions. Is there a problem with continued operation with this warning? Is there something that I can do to repair it.

Howard Neuschaefer [email removed]@sbcglobal.net

Firefox won't open. System says it can't find VCRUNTIME140.DLL. There are SEVERAL copies on the drive. I believe I Refreshed and Reinstalled? And still cannot run.

This is the first time Firefox has failed in years. There are no instructions for this specific problem. FWIW I just installed AURA seemingly without problems.

Richard PS - Wouldn't it be great if the library of proven volunteer responses was searchable? r