Microsoft’s July Patch Might Be to Blame If Azure VM Isn’t Loading

The security bug was introduced during Microsoft’s July 2025 Patch Tuesday rollout last week.

Microsoft has released an emergency update to address a bug that prevents certain virtual machines hosted on the Azure cloud platform from launching when Virtualisation-Based Security (VBS) is enabled.

The bug was introduced by a fix rolled out in last week’s July 2025 Patch Tuesday.

What could be affected by this Azure VM launch bug?

General Enterprise Azure VMs using the v8.0 configuration version and the Standard security type are potentially affected by the issue. The problem primarily impacts VMs where VBS is enabled, Trusted Launch is disabled, and the guest operating system is either Windows Server 2025 or Windows 11 24H2.

Users can open System Information (msinfo32.exe) to check if VBS is running and confirm that the Hyper-V role is not installed. They can also verify whether ...