Apple TV suddenly won't play Movies or Shows; music is ok

Have been happily using to watch both movies and shows, and listen to radio. Between episodes one night it just sat on "loading" without playing the show. I turned everything off, tried again the next night and it wouldn't play any shows or movies (even ones I've watched previously), just hung on "loading". iTunes Radio plays fine. Wifi signal is strong in settings, and plenty of download left.

Suggestions?