I have the same problem, it has worked for over a year now all of a sudden it doesn’t, I can watch trailers but films or programs just come up with the message Something went wrong, please try again later
This must be a copy protection issue. When you go to play the item the app has to confirm it's playing to a valid device. HDMI incorporates a handshake protocol that includes HDCP (High-bandwidth Digital Content Protection). This was 'enhanced' for HDMI when used for UHD devices.
Do you have a UHD or standard HD tv?
I've only had this issue once on an HD TV and the de-register / re-register + reboot fixed it.
Others have changed the V6 HDMI settings. You could try that with a reboot.