After a firefox Update it reported that for some reason all the tabs that opened fine before were crashing and unable to be opened so I closed the browser and opened it again,as that's fixed this problem in the past, and when I re-opened it my previous history and all my bookmarks were no longer there. I'm not happy that all my bookmarks and the tabs I had open at the time no longer exist and it doesn't seem to want to re-import the bookmarks from a backup either. Is there a way I can stop it from doing this?