User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:57.0) Gecko/20100101 Firefox/57.0 Build ID: 20171207194519 Steps to reproduce: - Install https://addons.mozilla.org/en-US/firefox/addon/youtube-subscription-checker/ - Open Firefox Preferences - Set Firefox to "never remember history" in the "History" section - Restart Firefox - Open the addon's page by using the icon it adds to the toolbar Actual results: The addon fails to open its IndexedDB and shows a screen about the DB being corrupted Expected results: Addon works normally. This might be the same issue as bug 1427041. This bug came from this comment https://addons.mozilla.org/en-US/firefox/addon/youtube-subscription-checker/reviews/1019025/