Hi, no idea. *https://support.mozilla.org/en-US/kb/how-do-i-choose-what-types-information-sync-firefox *https://support.mozilla.org/en-US/kb/firefox-sync-troubleshooting-and-tips Backup : *https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile *http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox Please Copy/Paste about:support to the Address Bar and Enter Go all the way to the bottom almost to Places Database and Click on Verify Integrity If still issues head to the top of the page and do Please try : SAFE MODE *https://support.mozilla.org/kb/Safe+Mode *https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes In Firefox Safe mode these changes are effective: *all extensions are disabled (about:addons) *default theme is used (no persona) *userChrome.css and userContent.css are ignored (chrome folder) *default toolbar layout is used (file: localstore-safe.rdf) *Javascript JIT compilers are disabled (prefs: javascript.options.*jit) *hardware acceleration is disabled (Options > Performance > Uncheck to view) *plugins are not affected *preferences are not affected TEST'''''''''is issue still there ? If still, Refresh is right there also : *https://support.mozilla.org/en-US/kb/refresh-firefox-reset-add-ons-and-settings