[German]Microsoft Hyper-V users running Windows Server 2012/R2 should be cautious about installing update security update KB5009586 or KB5009624 for Windows Server 2012/R2. The security updates released on January 11, 2022 have several unpleasant collateral damages at once. After installing the security updates, the Hyper-V host (Windows Server 2012, Windows Server 2012 R2 or Hyper-V Server 2012) can no longer be started. Here's an overview of what's currently known about this in reader comments from the blog and elsewhere.
Hyper-V fails after update installation
Regarding the German blog post Patchday: Windows 8.1/Server 2012 R2-Updates (11. Januar 2022), mögliche Boot-Probleme erreichten , I received several reader comments complaining about a Hyper-V host not starting. From user TomTom there is in this German comment with the following details (I've translated the text):
VM's on Server 2012 R2 Hypervisor do not start anymore.
The error message is that the hypervisor is not running.
In the event log is logged when starting the HyperV server: (ID 80, Hyper-V hypervisor)
Hypervisor launch failed; The operating systems boot loader failed with error 0xC00000BB.
Error was on multiple servers, KB5009624 uninstalled, hypervisor restarts normally.
And German blog reader Bernhard, who is also affected, told me the following:
Our 2012 Hyper-V server doesn't want after KB5009586 update either!
"Error while trying to start the selected virtual computers".
"Virtual computer XXXXX could not be started because the hypervisor is not running."
After uninstalling KB5009586 it runs again, but unfortunately it crashed the Linux virtual machines, so by means of Restore they had to be restored.
German blog reader Bruno Studerus wrote in this comment:
We also had the same problem with KB5009624 on a customer installation with Windows 2012 R2 this morning. The virtual Hyper-V hosts could not be started.
Error message then: Error during initialization: The virtual computer could not be started because the hypervisor is not running.
Removed the service pack KB5009624 from the server and restarted the host server. After that the virtual Hyper-V servers worked again. The KB5009624 now immediately excluded from the Windows updates.
And another thing: HyperV cluster: Livemigration broken.
After uninstallation ok again..
In all cases, the only solution I know of is to uninstall the January 11, 2022 security update.
Microsoft Office Updates (January 4, 2022)
Microsoft Security Update Summary (January 11, 2022)
Patchday: Windows 8.1/Server 2012 R2 Updates (January 11, 2022), boot loop reported
Patchday: Windows 10 Updates (January 11, 2022)
Patchday: Windows 11 Updates (January 11, 2022)
Patchday: Updates for Windows 7/Server 2008 R2 (January 11, 2022)
Windows Server: January 2022 security updates are causing DC boot loop
Windows VPN connections (L2TP over IPSEC) broken after January 2022 update
Windows Server 2012/R2: January 2022 Update KB5009586 bricks Hyper-V Host
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