I am suddenly unable to watch movies and TV shows on Apple TV on my Macbook (Macbook Air 2017, 13 inch, if it makes a difference). It keeps asking me to log in and re-authorize, then a message pops up about “This movie can only be played on displays that support HDCP (High-bandwidth Digital Content Protection).” Is there something I can freely download to watch all the stuff I paid iTunes good money for years ago? WTF happened?
You’re watching the movies on the MacBook screen, not an external display, right? Did you authorize by selecting Account > Authorizations > Authorize this Computer in Apple TV? If that doesn’t work, try booting in Safe Mode. If that fixes it, then probably one of your startup items is causing the problem and you’ll have to track down which one it is.
Are you using an external display? HDCP is the protocol used to ensure end to end control of the data stream to prevent copying. Old displays may not implement HDCP and so the system will be unable to create the required end to end handshake. There are also two versions of HDCP. Everything needs to support version 2.2 for 4k content. Otherwise it falls back to 2k (1080p) as the highest resolution.
Any reasonably new display should work.
Another problem with an external display can be a poor cable. HDCP runs over a somewhat badly specified interconnection in the cable and can have problems.
Viewing on the laptop screen itself should not be an issue.
It’s my laptop screen. My best guess is, last time I tried to clear out my cache, I deleted something I shouldn’t have. The problem seems to be fixing itself kind of slowly; TV shows I deleted years ago are suddenly back in my account and the show I want to see but can’t is inching towards self-repair.