Default [Q] Off-line viewing

I downloaded a movie from Google play and saved it for offline viewing. Problem is when I try to use chromecast to view the movie. It tells me I must remove the download first. Since I am in a hotel I am unable to use "streaming" with chromecast since the router will not allow my tablet and chromecast see each other on the network. I am using my phone as a router in order to stream downloaded content.

Does anyone know how to get Google play to allow me to play the downloaded file?