Refer to the first article below for how to seek support. You would probably save yourself a lot of time by creating a new profile. You can do that with Firefox closed. https://support.mozilla.org/en-US/kb/firefox-crashes-asking-support https://support.mozilla.org/en-US/kb/profile-manager-create-remove-switch-firefox-profiles#w_start-the-profile-manager-when-firefox-is-closed https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data#w_what-information-is-stored-in-my-profile