New Windows Server updates break Hyper-V

The latest Windows Server updates are causing severe issues for administrators, with some controllers rebooting and Hyper-V not running until the updates are rolled back. This bug primarily affects Windows Server 2012 R2 server

Yesterday, Microsoft released the Windows Server 2012 R2 KB5009624 update, the Windows Server 2019 KB5009557 update, and the Windows Server 2022 KB5009555 update as part of the January 22 Updates.

The only known fix at this time is to uninstall the update. A quick uninstall can be done with one of these commands in PowerShell for your operating system.

Windows Server 2012 R2: wusa /uninstall /kb:5009624
Windows Server 2019: wusa /uninstall /kb:5009557
Windows Server 2022: wusa /uninstall /kb:5009555