Error type: "Not Found". Error message: "The playlist identified with the requests
parameter cannot be found." Domain: "youtube.playlistItem". Reason: "playlistNotFound". Location type: "parameter". Location: "playlistId".
Did you added your own Google API key? Look at the help
Check in YouTube if the id UCNmC6HYJwU1UYq43jAAKs-Q
belongs to a channelid. If the user id is correct, check that the channel of the user has list of "likes". Check the FAQ
of the plugin or send error messages to support