Do you still have bookmark backups in the bookmarkbackups folder? *Bookmarks > Show All Bookmarks > Import & Backup > Restore *https://support.mozilla.org/kb/restore-bookmarks-from-backup-or-move-them Do you have an "Old Firefox Data" folder on the desktop in case you have refreshed Firefox and created a new profile? *https://support.mozilla.org/kb/reset-firefox-easily-fix-most-problems You can recover data form the "Old Firefox Data" folder, but be cautious. *https://support.mozilla.org/kb/Recovering+important+data+from+an+old+profile You can copy files like these to your current Firefox profile folder. * bookmarks/history: backups in the bookmarkbackups folder and possibly places.sqlite if you really need the history * other SQLite files like cookies.sqlite (cookies) and formhistory.sqlite (saved form data) * logins.json and key3.db (decryption key) for Passwords saved in the Password Manager * permissions.sqlite and possibly content-prefs.sqlite for Permissions and Site Preferences * cert8.db for stored intermediate certificates (Certificate Manager) * sessionstore.js for open tabs and pinned tabs and tab groups * persdict.dat for words you added to the spelling checker dictionary Note that "Reset/Refresh" creates a new default profile with a time stamp appended to identify it and tries to recover settings like bookmarks and history and passwords and history and cookies and auto-fill data from the old profile, but you lose data like installed extensions and other customizations. The current profile folder will be moved to the "Old Firefox Data" folder on the Desktop. *http://kb.mozillazine.org/Profile_folder_-_Firefox