I’ve been enjoying Returnal recently, but I’ve had a ton of technical issues with it. Half the time when starting the game, or performing certain actions, it would just hang at a black screen. Sometimes, the game would be still running and updating the system resource monitoring, but be completely unresponsive.
Turns out if you’re running Windows 10 LTSC, you lack the VP9 codec, which the cutscenes are in. The black screen is because it can’t play the cutscene properly. (Any bits about DX11/DX12 seem to be red herrings.) The VP9 codec is on the Windows Store, but since you don’t have that in LTSC, you can install it via other means. For example, this dump in the Internet Archive contains the codecs you’re looking for; install them, and after a reboot, things should work again.