Microsoft has had to pause issuing the Windows 11 24H2 update to users who have certain Ubisoft games installed on their PCs as the games become unresponsive. Here's the blurb from the help article:
After installing Windows 11, version 24H2, you might encounter issues with some Ubisoft games. 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
Avatar: Frontiers of Pandora
Note: Ubisoft released a temporary mitigation for Star Wars Outlaws to prevent the game from failing and stop responding. You might still experience some performance issues.
To safeguard your Microsoft Windows update experience, we have applied a compatibility hold on devices with these games installed. These devices will not be offered to install Windows 11, version 24H2 via the Windows Update release channel. IT administrators using Windows Update for Business reports can check these issues using the following safeguard IDs: 54437462 and 54580160.
Important: We recommend that you do not attempt to manually update to version 24H2 using the Windows 11 Installation Assistant or the media creation tool until this issue has been resolved.
If you are already affected by the issue, the best workaround is simply to close down the game via the Task Manager if it has hung up. Microsoft and Ubisoft are currently working on a solution, and we'll update this story once it becomes available.