For about a few weeks now, videos that are listed as 18+ can’t be played on W2G. It’d be great if you could find a way of making it possible again, because there are more and more videos that are being flagged as 18+.
This was a change on Youtube’s side. 18+ video no longer play on any embedded player on any site. Using W2gSync is the only availble workaround for the moment. Age-restricted content - YouTube Help