Microsoft releases update for bug that breaks Hyper-V VMs on Windows Server

Microsoft has released an update for a bug in Windows Server that could occur after installing the latest Patch Tuesday patch. This bug prevented the creation of certain virtual machines in Hyper-V. The patch is not installed automatically.

Microsoft has released out-of-bands updates for Windows Server 2019 and Server 2022. For Server 2019 there is KB5022554for Server 2022 KB5022553. Only Server installations using Software Defined Networking through the System Center Virtual Manager are susceptible. Users affected by the issues should install the patches on all Hyper-V hosts in their environments.

The problems arose after the monthly Patch Tuesday round earlier this month. It is the second time in a short time that Microsoft has had to send an out-of-bands update as a result of that patch round. Earlier this week, some Windows 10 users were already getting a blue screen of death after the update.

Microsoft is not sending the two new updates through Windows Update as it normally does. The company says that users themselves can change the KB numbers in the Update Catalog need to find and install them manually. Administrators also do not need to roll back the earlier Patch Tuesday update.