Is it possible that a new blank profile was created? Look on your desktop. Do you see a folder called; '''Old Firefox?''' https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles https://support.mozilla.org/en-US/kb/how-run-firefox-when-profile-missing-inaccessible ------------- Type '''about:profiles'''<enter> in the address bar. How many profiles are listed? How many should be there? http://kb.mozillazine.org/Profile_folder_-_Firefox#Navigating_to_the_profile_folder https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles https://support.mozilla.org/en-US/kb/how-run-firefox-when-profile-missing-inaccessible https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles

Were you using separate profiles for the DE and other Firefox (release) versions? Note that Firefox DE can use its own profile (xxxxxxxx.dev-edition-default) and thus shouldn't interfere with profiles used by other Firefox versions.