Similar deal here as well. Upgraded to Firefox 3.6.8 and lost all bookmarks and even the history function wouldn't work. Tried to restore from backup folders and kept getting an error message. Also tried talking to the Firefox tech support thru live chat and they shut down my question saying no fixes were available, very frustrating and poor customer service. Almost said, f*** Firefox and switched back to Safari. However, there is hope! Delete current Firefox from your computer and download a previous version (ie. Firefox 3.5.11). Make sure to remove all folders to the trash. I then restored them after the download to a folder on my desktop titled "Bad Firefox." Once I completed the download of the older version then you should be able to restore your bookmarks from the previous backup folder. Lesson learned going forward, be weary of updates, they can bite you in the ass sometimes!

Thanks Josh. I was so frustrated, I finally deleted firefox, app and all files and reinstalled. I did import my bookmarks from Safari, which were pretty similar. Probably lost a few, but felt it was my best option. Everything seems to be working properly now; hopefully, it will stay that way. Thanks again, best of luck!

I have a user who is going through the same issue.

I renamed the bookmarks.html which will open and show me the bookmarks however, they do not appear within firefox.

I have the same problem; lost start page, bookmarks and toolbars.

I was so frustrated after trying many suggested solutions. Ultimately, I completely uninstalled firefox and then had to reinstall from scratch. I did import my bookmarks from Safari, which were similar and just had to swallow losing the rest. If it happens again in the future, will probably just give up on firefox.