Firefox Community Forum

I cannot get into Firefox due to an error message that keeps coming up. Your Firefox profile cannot be loaded. It may be missing or inaccessible.

I have tried deleting and reinstalling it, but it didn't really uninstall completely. I have tried a few suggestions from online, which didn't work. I also tried right clicking on the Firefox symbol and went into some of the different options, but nothing worked for me.

I had been using the Mozilla Firefox VPN for a few weeks, but now it will not launch. I sign in without a problem but when I click on the VPN icon on the toolbar, nothing happens. I just get the pop-up to try the VPN and "Get Started" (see attachment).

Please advise.

I got so frustrated with not being able to reinstall Firefox because I kept getting the error message "Your Firefox profile cannot be loaded. It may be missing or inaccessible". So I deleted all the profiles after copying them to an external hard drive. Then I copied the file ending in.test from the Old Firefox data folder on my desktop to the AppData/Roaming/Mozilla/Firefox/ profile. Then I copied the biggest file ending in .default from the backed up Local profiles to the AppData/Local/Mozilla/Firefox/ profile. It doesn't matter if I delete or keep the Old Firefox data folder on my desktop, I still get the Profile Missing error message. What can I do, so my laptop would appear as if it had been powered up straight out of the box and never had Firefox initially installed or what do I do with my profiles to make them accessible?

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

i downloaded the installer on windows 11 and it would not go up. it just stayed at 0%. and i wet t the fallback download and that worked but the download downloaded Firefox but yet it opened for 2 seconds and closed. and refused to open from that point! what do I do?

Firefox cannot start because Mozilla process is already running and I cannot stop it.

I tried to restart my PC but no success. I reinstalled Mozilla/Firefox but again error message appears:

"Firefox is already running, but is not responding. The old Firefox process must be closed to open a new window."

latest update from 150.01 to 150.02 crashed compatibility error can't open firefox. error platform version 150.01 is not compatible with minver>=150.02. can't even open anymore

I have been with Firefox for years as default browser but recently been having probs. It wont open from Start or my taskbar. Keeps going to New tab at top of screen. Tried reinstalling but still the same. What has happened?