I'm using Firefox 40.0.1. I have a couple of old Firefox profile backups (from 2010, which would be Firefox 3 I believe). I attempted to restore the places.sqlite file to see history and bookmarks from it, but as soon as I start Firefox it creates a places.sqlite.corrupt file and restores nothing. I've tried copying over the entire profile as well. I downloaded the places maintenance add-on and ran all of the checks but it didn't fix it. I've also tried going to Bookmarks -> Import and Backup -> Restore, but it's unable restore any of the bookmarks. I don't believe these files are actually corrupt, because I have two profile backups from separate computers and neither of them work. Also, they're from full backups that I made of those computers at the time, and none of the other files on the backups are corrupt. Is there some incompatibility issue possibly? The only "places.sqlite" files that the backup contains are places.sqlite and places.sqlite-journal. I should also note that one of these profiles is from a Linux system, and the other from a Windows XP system. Thank you.