Problem booting Windows 2012R2 VM on Windows 2025 Hyper-V

Problem booting Windows 2012R2 VM on Windows 2025 Hyper-V

one of the customer, which running on the Windows Server 2025 Failover Cluster and have 3 identical nodes and shared SAN storage have problem with booting of the Windows Server 2012 R2 Guest VM. Few months ago we move that VM from the old cluster, which was on the WS 2019, and rebooted the Guest VM with 2012 R2 many times. 

Today the customer rebooted the affected VM with WS2012R2 guest OS, and VM not boot anymore. All nodes in the cluster have same patches from Windows Update. 

We tried move VM between failover cluster nodes, but situation was same – The error is a blue screen 0x7B (INACCESSIBLE_BOOT_DEVICE). So  we used the Commvault to restore entire VM, but that restored VM not boot anymore 🙁 

One of the nodes was „paused“ so we decided to uninstall latest security update (KB5060842) and reboot the node. 

After the reboot of the node, we moved affected VM to the node, where the KB5060842 was uninstalled and VM started successfully.

I hope, that helps someone 🙂