Works when clicking on a link directly but doesn't when opening a youtube video in a new tab. What's odd is it used to. I recently had to reinstall windows. Somethings changed, I don't know where... possibly at youtube because this addon used to work on videos opened in new tab. Note: None of the 'stop auto play addons' (if that's what they are?) work on videos opened in a new tab anymore so possibly youtubes changed something.