Microsoft has released emergency updates to Windows Server to address a known virtual machine (VM) creation issue after installing this month’s Patch Tuesday updates.
The issue only affects VMs that are managed through System Center Virtual Machine Manager (SCVMM) and use software-defined networking (SDN).
On affected systems, Windows administrators see warnings during live migration, SLB Load Balancer or SDN RAS Gateway fails, and failures when creating new VMs and connecting virtual network interface cards (VNICs).
Only Windows Server 2019 and Windows Server 2022 should be affected after installing the December 2022 Patch Tuesday updates (KB5021237 and KB5021249).
To resolve this issue, administrators should install the OOB cumulative updates that were released for their systems today on all affected Hyper-V hosts in their environment.
“You do not need to install any updates or make any changes to other servers or client devices in your environment to resolve this issue,” Microsoft said Tuesday.
OOB updates are not delivered through Windows Update
Today’s updates are not delivered through Windows Updates and will not be automatically installed on affected servers.
To get the standalone package, you need to search for the KB number in the Microsoft Update Catalog, download them, and install them manually.
They can also be manually imported into Windows Server Update Services (WSUS) and Microsoft Endpoint Configuration Manager.
Microsoft also provides instructions for importing updates from the Microsoft Update Catalog into WSUS and Configuration Manager.
The list of Windows Server cumulative updates released today includes:
“You do not need to apply any previous updates before installing these cumulative updates,” Redmond added today.
“If you have already installed the updates that were released on December 13, 2022, you do not need to remove the affected updates before installing any future updates, including the updates listed above.”
An interim fix is also available for administrators who cannot immediately install today’s updates on affected SDN-based SCVMM deployments.
This workaround requires running a series of commands on all SCVMM-managed Hyper-V hosts from an elevated PowerShell window (immediately after installing updates KB5021237 and KB5021249).
You can find large-scale deployment scenarios on an SCVMM management server and more details on how to deploy the solution in this support article.