I was happily browsing when suddenly Firefox just crashed - just disappeared with no warning or alert that "Firefox has encountered a problem...." or other such notice. I clicked on my shortcut to open it again and found that Firefox reopened but as an entirely new browser. There were no bookmarks; no history - no anything - just a new browser as if I'd never used it before. So what happened and how can I get my 600+ bookmarks restored? (I have imported many of them from my Chrome browser but they were out of date and many new links were missing) The one thing that had just happened was that I'd just updated 10Bit's Advanced System Care 9 and I'm wondering if this was the cause? However, apart from some vague connections in internet forums I couldn't find out if that was the cause of the problem - and anyway, it doesn't solve the disappearance of my favorites. Any help will be appreciated.