Hi, Please try this: '''Tools''' ('''Alt''' + '''T''') > '''Clear Recent History''', choose '''Everything''' in '''Time range to clear''' and '''Cache''' and '''Cookies''' under '''Details''' and '''Clear Now'''. [https://support.mozilla.org/en-US/kb/Clear%20Recent%20History Clear Recent History]. If the problem persists, please check if this happens in [https://support.mozilla.com/en-US/kb/Safe%20Mode Safe Mode.] [http://kb.mozillazine.org/Problematic_extensions Problematic Extensions] [https://support.mozilla.com/en-US/kb/Troubleshooting%20extensions%20and%20themes Troubleshooting Extensions and Themes] [http://support.mozilla.com/en-US/kb/Uninstalling+add-ons Uninstalling Add-ons] [http://kb.mozillazine.org/Uninstalling_toolbars Uninstalling Toolbars]