Hi, sorry to hear about this issue as well as non-response to you. How did you contact us regarding the Yahoo issue ? You mention email. This is the only method of contacting Firefox Support which is through this forum. Please save a copy of your Profile : *https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data It is not recommended to use 3rd party uninstallers such as Revo https://www.revouninstaller.com/revo_uninstaller_free_download.html After uninstalling please use this URL to get Firefox 59.0.2 *https://www.mozilla.org/firefox/all/ Please try inserting your Profile as per 1st URL, if it does not : *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 the problem. Never work with original files. *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 let us know if this solved your issue or if need further assistance.