iTunes won't play movies

[macjoshua]

In iTunes, when I try to open a movie, I just get a black screen. A couple times, I've had a dialogue box pop up saying "The selected movie won't play on your display. This movie can be played only on displays that support HDCP.” I have a 2017 15" MacBook Pro, so my hardware should be more than sufficient. I've tried doing a PRAM reset, SMC reset, and even reinstalled Mojave. Any other ideas?

 

[rbrian]

In iTunes, when I try to open a movie, I just get a black screen. A couple times, I've had a dialogue box pop up saying "The selected movie won't play on your display. This movie can be played only on displays that support HDCP. I have a 2017 15" MacBook Pro, so my hardware should be more than sufficient. I've tried doing a PRAM reset, SMC reset, and even reinstalled Mojave. Any other ideas?

Ah, the wonders of DRM, which only punishes the innocent. HDCP is a security technology designed to prevent you copying videos, by only playing on a compatible display. If it doesn’t detect the security signal, it won’t play. I’ve had similar problems on my TV, which I traced to a loose HDMI cable - but it shouldn’t ever happen with a built in laptop screen.

 

[purged]

Absolutely.

 

[macjoshua]

Your issue actually arose from doing the PRAM reset. This has been a pretty serious and under-reported bug with recent models for some time. Your Amazon movies and Netflix will not play either. It's a problem with something in the firmware related to HDCP; last I heard they are aware and working on it, which means any action is a year or two away from experience. Anyways, here is the band-aid fix, apply after each and every PRAM reset:

https://discussions.apple.com/thread/8427286

Thank you! That solved it. PRAM resets used to solve problems, not create them!