Hi, I want to update this add-on to version 6: https://addons.mozilla.org/en-US/firefox/addon/video-downloadhelper/ The update should introduce a completely new UI but it isn't applying for me, even after multiple re-installs of the add-on. There might be cached files in my Firefox profile. With a freshly created profile it works as expected. Is there a way to clear the extension-cache of Firefox?