Problem solved: movie files need to have file name extension. Can I somehow force the Apple TV to reload the screensavers URL? Are there any size / quality limitations on what movie files it will play? Can the locally stored / cached movies be erased to force a download of the new movies? Is there a way to get some feedback from the Apple TV as to whether it has fetched the latest JSON file? The Apple TV has been on permanently, so would have had ample time to download the new movies, and the movies have been available (and play fine on the iPad, or MBP, using the URLs from the JSON file. My version of the JSON file is located here:, you can compare this with Apple's own version here:, I think the syntax is OK in mine. I have both 1080p versions (about 600MB per movie) and 720p versions (about 70MB per movie) available. But I changed the URL since then, and the Apple TV for several days has not downloaded any of the new movies. This worked one time for me and one of my own movies was downloaded. This enters a store/channel mode, which allows when selecting channel mode to specify the URL where to fetch the movies from via an intermediary JSON file describing the download URLs. For that you have to go into settings, move to about, while on about, click Play/Pause 4 times. On the 4th gen Apple TV you can select a custom json file URL to load screensaver movies other than the apple ones.
