Firefox Community Forum

I downloaded firefox and it worked for about a month. Now when I try to launch it, the screen flashes momentarily as though it were about to pop up, but then it does not actually open a browser window. I have uninstalled and reinstalled firefox more than once, I've tried a simple restart of the computer, and tried multiple different update methods (updated windows). Any suggestions?

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!

When I try to launch firefox, it opens only on the taskbar for a split second and doesn't launch. I don't see the program appear at all on task manager. I've restarted my computer and reinstalled multiple times. This problem persist across multiple computers

Firefox refuses to open. What happens is, It'll open for like 1 frame and then close. This happened to Chrome last month too, which is actually why I installed Firefox. I have to uninstall it, then reinstall it from the website. If that doesn't work, I try the Microsoft Store. If that doesn't work either, I keep switching between them until it eventually opens. It breaks again when I turn off my computer. Thanks.

Hello,

I have the latest version (140) of Firefox installed on a Windows 11 laptop with the latest Windows updates. It works fine for my user (who, BTW, has admin privileges) but it won't even start for my wife's Windows user. To be precise, "won't start" means that when you try to launch it it sometimes looks like it's trying to create a window but immediately closes it with no error messages, no crash reports, no logs, nothing at all. It won't even start from the Run menu with any command line flag like -p, -ProfileManager or even -safe-mode, I tried all of them.

Other things I've tried: 1) Check the Windows event logs. Nothing. 2) Run sfc /scannow to check for corrupt system files. 3) Uninstall Firefox, delete the Program Files\Mozilla Firefox folder, and re-install it. 4) Move the entire Firefox folder inside %appdata% to a temporary folder outside users. Firefox recreates it, creates 2 new profiles and dies silently again! 5) ...and a lot of other things that I read online and do not remember anymore.

At this point I'm at a loss and I'm an IT guy. Of course I have no idea how this happened, the browser used to work fine up until a week ago or so. Other software that might interfere is Malwarebytes, but it works fine for my user, so... 🤷🏻‍♂️

Thanks in advance for any ideas.

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