Sorry to hear about this problem. Your Firefox reported that it is version 46, so I'm not sure what kind of update occurred. Could you clarify? The format of the bookmarks-history file (Places database) changed around the time of Firefox 56. You probably cannot use the database from Firefox 56+ in an earlier version. If your Firefox updated to a version newer than 55 and you downgraded to a version older than 56, that could be the problem. Can you update to a current version higher than 55, either: * Regular release, Firefox 61: https://www.mozilla.org/firefox/all/ * Extended Support Release of Firefox 60: https://www.mozilla.org/firefox/organizations/all/ (see: [[Switch to Firefox Extended Support Release (ESR) for personal use]]) If that's not possible, you could try converting a recent bookmark backup file to an HTML-format file: * Conversion tool: https://www.jeffersonscher.com/res/bookbackreader.html * Import steps: [[Import Bookmarks from an HTML file]] But for security reasons, you should update.