A possible cause is a problem with the file places.sqlite that stores the bookmarks and the history. *http://kb.mozillazine.org/Bookmarks_history_and_toolbar_buttons_not_working_-_Firefox

Do you have all your bookmarks in the sidebar (Ctrl+B), if you do there is nothing wrong with your places.sqlite as far as bookmarks go, next check to see if you have history in the sidebar (Ctrl+H) And before you consider deleting or renaming your places.sqlite If you are using an external monitor with a laptop try moving the library window back to the laptop. Try searching on just a colon ":" in the bookmarks Library List. * https://support.mozilla.com/questions/792065 Try in Firefox Safe Mode to make sure extensions are not part of the problem. May fix problem -- not likely but you have a lot to lose if you lose data from places.sqlite so worth the trouble to try first. * Corrupt localstore.rdf - MozillaZine Knowledge Base *: Back/forward can't be moved *: http://kb.mozillazine.org/Corrupt_localstore.rdf Next try a bookmarks backup and restore, this may fix problems, I've never had to delete or rename my places.sqlite file yet, which would lose history, which is needed for the AwesomeBar to work properly or anything else that involves history. # Ctrl+Shift+B to bring up Library List # Import and Backup # Backup to c:\temp\bookmarks-2011-08-18.json (or whatever current date is) # Import and Backup # Restore > choose file > c:\temp\bookmarks-2011-08-18.json # see if problem is fixed If you still have problem then look to other solutions before even considering deleting/renaming places.sqlite the problem could be in several things also mentioned in the * http://kb.mozillazine.org/Locked_or_damaged_places.sqlite