Did you possibly used the refresh feature in Firefox and created a new profile ? when you use the refresh feature in Firefox then a new profile is created and some personal data (bookmarks and history, Form Data, tabs) is automatically imported. The current Firefox 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. *https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile ---- See also: *https://support.mozilla.org/en-US/kb/recover-lost-or-missing-bookmarks *https://support.mozilla.org/en-US/kb/recover-user-data-missing-after-firefox-update

I found out if you type about:profiles in the address bar profiles will pop up and if you have two profiles one will contain what has been lost.

Has your problem been solved?