Printers, webcams, routers—the usual things that have issues after a big operating system patch. For the Windows 11 24H2 update, games also joined in with the failure party, specifically five big releases from Ubisoft and the problems were so bad, that Microsoft prevented the update from being applied to any PC with those games installed. Ubisoft has released hotfixes for two of them but Assassin's Creed Origins, Odyssey, and Valhalla are still without a solution.
Microsoft has confirmed that Ubisoft's temporary patches for Avatar: Frontiers of Pandora and Star Wars Outlaws resolve problems with crashes, though you still might experience performance issues. That means if you have either of those games installed (fully patched, of course) then you'll eventually be offered the Windows 11 24H2 update, should you be using that operating system.
