Can't play rented movies using AirPlay
MacBook Pro with Retina display, OS X Mountain Lion (10.8), Synology NAS, Airport Extreme
MacBook Pro with Retina display, OS X Mountain Lion (10.8), Synology NAS, Airport Extreme
I got the same thing. This happens when the movie is not fully downloaded yet. This article explains that the movie must be fully downloaded to stream it to your Apple TV through AirPlay: About renting movies from the iTunes Store - Apple Support
Can't play rented movies using AirPlay