Firefox Community Forum

I am on Windows 10 Pro (extended to Oct 2026) and use the Firefox profile manager at startup since I have more than one profile. Today (11/12/2025) I attempted to start Firefox and the profile manager window would not populate. the window was blindingly white on my dark background. I closed and restarted umpteen times but it refused relentlessly. I was about to uninstall firefox and then decided to see if I had actually installed it on any of my mobile devices. And indeed I had it on my ancient Apple iPhone 7+. And it was synced! I refreshed the sync and indeed it picked up my most recent activity from last night. All tabs were synced. To make sure I had another synced copy I also installed it on my iPad. I synchronized this too and suddenly my desktop browser started working again.

I don't know what caused the lockup of the Profile Manager but I am afraid it might happen again. What causes this and what can I do to regain control without having to reinstall? I am a researcher and I have over 1000 tabs open.

There was a Microsoft update to Windows 11 today. Immediately after that, Firefox keeps giving me message that cannot restore tab. I close tab and try to open Firefox again and again get message that cannot restore tab. How do I fix Firefox so it works again?

I got a random pop up on Firefox that I clicked without fully reading it, which closed Firefox and then prompted me for the administrator password (aka the password of that account on my laptop) so Firefox can install a helper tool. I did, and it did nothing. Every time I try to open Firefox I get the same pop up prompt and no matter how many times I give the password nothing happens, and I can't open the application. Clicking cancel on the prompt also does nothing.

I logged onto a different account on my laptop and can use Firefox like normal, but none of my settings/bookmarks/passwords from my other Mac account are saved here.

I would just delete and reinstall Firefox on the administrator account that is having this issue, but I don't know if I have anything properly backed up on Firefox, and I have a ton of things saved on there that I really don't want to lose. What do I do? Please help :(

Last screenshot is what happens when I try to launch Firefox and enter the password when the install helper prompt pops up