If you have submitted crash reports then please post the IDs of one or more recent crash reports that start with "bp-". *bp-xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx You can find the report ID of recent crash reports on the "Help > Troubleshooting Information" page (about:support). *click the "All Crash Reports" button on this page to open the <b>about:crashes</b> page and see all crash reports. Alternatively you can open about:crashes via the location/address bar. See also: *http://kb.mozillazine.org/Mozilla_Crash_Reporter *https://support.mozilla.org/kb/Mozilla+Crash+Reporter ---- Did you use built-in Firefox means to clear that data or did you use external cleanup software? Try to start Firefox in <u>[[Safe Mode|Safe Mode]]</u> by holding down the Shift (Mac: Options) key to see if that helps. Create a new profile as a test to check if your current profile is causing the problem. See "Creating a profile": *https://support.mozilla.org/kb/profile-manager-create-and-remove-firefox-profiles *http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Profile_issues If the new profile works then you can transfer files from a previously used profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over problems. *http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox