Did you lose the bookmarks? *http://kb.mozillazine.org/Lost_bookmarks Firefox stores the bookmarks and the browsing history in a SQLite database file named places.sqlite.<br /> There are 10 rotating daily JSON backups (bookmarks-####-##-##.json) in the bookmarkbackups folder within the Firefox profile folder, one for each day that Firefox is started. *http://kb.mozillazine.org/Backing_up_and_restoring_bookmarks_-_Firefox You can check for problems with the places.sqlite database file in the Firefox profile folder. *http://kb.mozillazine.org/Bookmarks_history_and_toolbar_buttons_not_working_-_Firefox *https://support.mozilla.org/kb/Bookmarks+not+saved#w_fix-the-bookmarks-file ----- You can also check the Time Machine on Mac *http://www.apple.com/support/timemachine/ *http://kb.mozillazine.org/Profile_folder_-_Firefox