I have a tvOS video app which has DRM implemented. I do not get any errors from ContentKey methods and video plays fine most of the time. But sometimes, the audio and video both don't work but only the progress bar continues. The only error that I get are:
MSVEntitlementUtilities - Process AppName-tvOS PID[283] - Group: (null) - Entitlement: com.apple.mediaremote.external-artwork-validation - Entitled: NO - Error: (null)
I was unable to find any information on when this error appears.