Sorry I personally can not help solve this. Best I can do is make comments & suggestions. If you know enough about places.squlite (I do not) it may be possible to hack it back into shape, with a SQL tool, using a spare copy of course. Trying the addon ''places maintenace'' is worth a try. It is probably also of interest to see what that addon's text log file reports, before and after running a repair attempt, and comparing it with your investigation. * https://addons.mozilla.org/firefox/addon/places-maintenance/ I do not follow development issues enough to know whether there are any plans to add a feature to backup history separate from places.sqlite. Possibly someone on one of the other fora may be able to answer that *https://www.mozilla.org/en-US/about/forums/ We are only fellow users of Firefox here, not developers; so do not discuss development policy or issues. I would be interested in a link if you find an answer. Maybe you are able to recover a working places.sqlite by using Windows previous versions. If it is recent enough you could restore the latest bookmarks back up into that and will not have lost much history. Again backup original files if important before attempting this. * http://windows.microsoft.com/en-us/windows/previous-versions-files-faq