Hello, Sorry to hear about that. First, Firefox automatically creates backups of your bookmarks, which can be helpful if your bookmarks are lost or missing. Click the Bookmarks button Bookmarks-29 (or New Fx Menu > Bookmarks) and select Show All Bookmarks. At the top of the Library window, click on Import and Backup and select Restore. Click the date of the bookmark backup you want to recover. In the new window that appears, click OK. Your bookmarks from the selected date should now be restored. https://support.mozilla.org/bm/questions/1027158#:~:text=First%2C%20Firefox%20automatically%20creates%20backups,bookmarks%20are%20lost%20or%20missing.&text=%3E%20Bookmarks)%20and%20select%20Show%20All,and%20Backup%20and%20select%20Restore.&text=Your%20bookmarks%20from%20the%20selected%20date%20should%20now%20be%20restored.