This video is in a format that can’t be viewed on your tv

Trying to view purchased, downloaded video using AirPlay from iPad Pro to Apple TV 4th gen.

The iPad screen mirrors to the TV, I select and play the movie, I briefly see a ‘time bar’ across the bottom and a spinning wheel. Then I get the error message:

”This video is in a format that can’t be played on your TV”.

Any questions or suggestions?

A little more detail... I use this set-up at my remote home. I have no real internet. I have only poor cellular service for limited data. There is a WiFi network within the home (for wireless printing, etc), but no internet service. I download content to the iPad so i can watch movies when I’m hear.

Airplay works for all other functions. I can play music, view my iPad screen, view photos and other videos. It works for everything but the downloaded movies. The movies play fine on the iPad Pro.

ideas?

Thanks... Joe in Maine