Installed new tvOS, and seemed to be working fine during install. Now only white screen. Still responds to the sleep mode button and volume, but nothing else. Pure white screen.
After Install, only white screen
Same here, installed and it rebooted to an all white screen and even after sleep an all white screen, same after a reboot. Can't use my apple tv 4 now.
See Apple reply on the subject (last post from BTH) : https://forums.developer.apple.com/thread/78577
Occurs for people using OTA update with SSO enabled.
Should prefer iTunes restore for now.