Hello Everyone,
I just came across this forum after having the exact same error message trying to play Gemini Man with Plex on my Android TV box (not Shield, but Ugoos AM6 Plus), “Not enough CPU for conversion of this item.”. I’ve tried to play it locally on the box with MX Player and it worked flawlessly, but with Plex app over 1 Gigabyte LAN it does not. Not sure why Plex tries to transcode this video, maybe because Plex is not able to handle high frame rate? Definitely not HDMI cable issue. Other 4K movies play fine.
