Set up a new Bravia 850C tv yesterday and I'm having problems with all UHD content. Sad (but glad) to see others having the same problem. I've spent an hour on the phone with Amazon tech support to no avail.

According to tech support, my tv didn't register when i authenticated the app. I'm guessing that's the problem. When I go to my profile on Amazon.com it doesn't show my TV as a registered device. Funny that the non-UHD content works regardless. Must have just put additional security in place for the UHD streams, and they "forgot" that there are Android devices with UHD clients other than FireTV.

I think your device doesn't get registered with Amazon unless you access the Amazon App Store from the device. Since that's not available on Android TV, maybe that's the issue?

I'd love to hear from an 850C owner with a 2nd gen FireTV.

Happened to me last night. Same situation. Same TV. Same show. Other shows are fine.

For anyone googling this in the future... Everything started working again without explanation.

It was clearly an issue on Amazon's side, but there's clearly no mechanism to get past the call screener obfuscation to let them know. Just be patient.