Take care. If you are getting that message it is probably whilst trying to Restore Firefpx .json or .jsonlz4 files and they will overwrite whatever you have now. *Please ALWAYS manually backup your bookmarks before attempting any restore. ** [[Restore bookmarks from backup or move them to another computer#w_manual-backup]]'''_manual-backup''' * Note also that the Restores overwrite. The HTML imports only tag on to existing listings ** [[Export Firefox bookmarks to an HTML file to back up or transfer bookmarks]] **[[Import Bookmarks from an HTML file]] Do you still have the old computer ? And is is working with a working Firefox installed ? Do you have the original Hard Disk drive or a backup image of that ? Are you trying to use Firefox Sync ?? Where did you get this backup file from and how did you try to restore it ? What instructions were you following ? Is the bookmark backup file from the old computer ? What version of Firefox was that is it an up to date Firefox 39 ? <br > Do you remember when approximately that computer and Firefox was last used ? See also * [[Restore bookmarks from backup or move them to another computer]] * [[Recovering important data from an old profile]]

You can check for problems with the <b>places.sqlite</b> 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 *Places Maintenance: https://addons.mozilla.org/firefox/addon/places-maintenance/