Try restore from a default bakuup: *[https://support.mozilla.org/en-US/kb/restore-bookmarks-from-backup-or-move-them#w_backup-and-restore Backup and restore] Or unhide the hidden files and folers: *[http://kb.mozillazine.org/Show_hidden_files_and_folders] Then go to your profile: *[https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data Profiles] Enter in bookmarks backups folder and copy one of that backups and try restore from it or try backup the places.sqlite and after restore it using SQLiteManager: *[https://addons.mozilla.org/en-US/firefox/addon/sqlite-manager SQLite Manager]

If you updated Windows then it is possible that an Old Windows folder (or something similar) got created to backup some data including your Firefox profile folder. *https://support.mozilla.org/kb/Recovering+important+data+from+an+old+profile Note that the "AppData" folder in Windows Vista and later Window 7+ versions and the "Application Data" folder in XP/Win2K are hidden folders. *http://kb.mozillazine.org/Show_hidden_files_and_folders