This add-on used to work. It doesn't now claiming that YouTube has changed its policies and so you can't download anything unless you upgrade to the premium version. Don't waste your time.
Pls. update to latest v 15.7, whenever youtube changes code every downloader out their breaks. This time it took longer for me to fix and then ever longer for mozilla to review and approve the update. If you find the addon working again, pls. re-rate the extension :)
