As reported by VGC, Microsoft updated its support website to reveal it has placed a temporary block on Windows 11 for users with those games installed.

“After installing Windows 11, version 24H2, you might encounter issues with some Ubisoft games,” Microsoft said. "These games might become unresponsive while starting, loading or during active gameplay.

"In some cases, users might receive a black screen. The affected games are Assassin’s Creed Valhalla, Assassin’s Creed Origins, Assassin’s Creed Odyssey, Star Wars Outlaws, and Avatar: Frontiers of Pandora.