Sounds that you have done a Refresh of Firefox and have created a new profile. When you Refresh/Reset Firefox then a new profile is created and some personal data (bookmarks, history, cookies, passwords, form data) is automatically imported. The current profile folder will be moved to an "Old Firefox Data" folder on the desktop. Installed extensions and other customizations (toolbars, prefs) that you have made are lost and need to be redone. It is possible to recover data from the "Old Firefox Data" folder on the desktop, but be cautious not to copy corrupted files to avoid carrying over problems. If the new profile is working and you have confirmed that you have all data that you need then you can remove this folder. 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 You can recover more personal data. *https://support.mozilla.org/kb/Recovering+important+data+from+an+old+profile You can use this button to go to the current Firefox profile folder: *Help > Troubleshooting Information > Profile Directory: Show Folder (Linux: Open Directory; Mac: Show in Finder) *http://kb.mozillazine.org/Profile_folder_-_Firefox