Forum der Gemeinschaft Firefox

SUBJECT: Profile missing after update to 146.0.1 

After the last Firefox update (146.0.1), I can no longer access my profile that included bookmarks, history and passwords.  

After the update was done on 12/19/25, I was given the option to choose between my original profile and a newly created one. The next day when I opened Firefox, there was only one profile shown and my original profile was gone. I have read numerous fixes for this problem but nothing seems to work.

I have done the following to try to locate my missing profile to no avail. 1. I went to the Profile Manager but the only profile listed was the newly created one. 2. I didn't do a refresh so there was no "Old Firefox Data" folder to copy the data from. 3. Used about:Profiles, Again only the newly created profile was listed 4. I used ~Library/Application Support/Firefox/Profiles. Still no luck. 

Could my profile have been moved to another place or could it be hidden? Any help would be greatly appreciated!

Dear Support Team,

I am writing to request assistance with an issue I encountered after a recent Firefox update. After opening the browser, an automatic updat led to making all of my bookmarks, saved passwords and website data disappear. The profile I was using had been active for over two years and contained important information that I now cannot access (it wasn't a profile I created myself, I just used the browser normally).

I have already tried several troubleshooting steps, including restoring previous profiles, checking the profile folder, and attempting to recover data from backups. Unfortunately, none of these attempts have been successful so far. The about:profiles website tells me my old profile does not exist but in my Firefox folder, there is a (profile?) folder from 2023 which contains only one file.

Could you please help me recover my previous Firefox profile or guide me through any additional methods that might allow me to restore my lost data?

Thank you very much in advance for your support.

Kind regards, Sophia

Whenever my laptop starts up,firefox with all of my tabs always starts up with it. When i rose up earlier in the day and started up my laptop firefox with all my tabs opened up as normal,but this evening everything is gone. I had at least 20 tabs open and they were all important. There was no option to recover the tabs and this isn't the first time this has happened,this is at least the third time that this has happened after the last year and a bit. This is incredibly annoying and frustrating. Is there even any point in asking the community how this can be resolved?

Firefox deleted many folders in my bookmarks file. Then, trying to straighten this out, Firefox has completely changed its home page layout and I can not manage it even in the simplest way. I want to restore everything to how it was two or three days ago.

After both a MS and Firefox update, I have lost all my Firefox bookmarks

I have viewed several videos online that showed how to restore them, they seemed straightforward enough, but I always hit a dead end.

Firefox>menu>Bookmarks>Manage Bookmarks>LIbrary>Import And BackUp>Restore>ChooseFile

Once I get to Restore, there are no dates available to me to pick from.All I get is Choose File, but when I click on that, nothing happens. Dead end.

Many thanks for any help. Jay

I have lost all my Firefox bookmarks. All gone. I have searched online for solutions, and have seen what appears to be a standard procedure for doing so. Bookmarks>Manage Bookmarks> LIbrary>Import and Backup>Restore

This is where it breaks down for me......I see no date available to use. All I see is "Choose File" and when I click that, nothing happens. That is the dead end I am at now.

Can anyone out there point me in the right direction? Many thanks. Jay

I opened a profile that I had just used recently to a blank tab bar. I closed it and the sessionstore-backup folder did not have a recent backup, The most recent about a week old.

Just for testing, I tried to restore with one of the upgrade.jsonlz4 file, about 2 weeks old, but it also had no session. I then restored one that was 2 months old. That one had a session

Now, Firefox no longer generates the upgrade.jsonlz4 files

I'm not exactly clueless, but I'm not an engineer. For some reason, I had three open Firefox/Mozilla browsers open on the taskbar but connected to one icon. Today, I've lost the browser with all of my frequently used sites, and tons of research, family, friends, World War II, finances, etc. The other two browsers had one tab, and maybe ten-fifteen tabs, respectively.

How do I restore the main browser?

Thank you for any assistance.