this is for windows but the same fixes apply as such, see the one at the bottom if all else fails.
http://support.mozilla.com/en-US/kb/The+bookmarks+and+history+system+will+not+be+functional Enda awr wrote: > Hi > > I'm on 2009.06 snv_111b X86 > > Firefox is displaying the message 'The bookmarks and history system will not > be functional because one of Firefox's files is in use by another > application'. This means Firefox is basically unusable for me now. I can > delete the user profile directory and make Firefox create a new one, but if I > reboot I'm back to the same problem. > > As far as I can tell, nothing changed, just booted up one day and Firefox is > broken...Can anyone perhaps tell me either what might be the problem, or how > to find out for myself what might be the problem? > > Thankyou -- Enda O'Connor x19781 Software Product Engineering Patch System Test : Ireland : x19781/353-1-8199718