Windows Server 2019 machines suddenly not starting

[haydenhancock]

I have several Windows Server 2019 virtual machines and none of them start anymore. I've can't attach the compressed logs because they are still too large. I am using VirtualBox 6.1.22r144080 (Qt5.6.2). I have a Windows 10 virtual machine that starts without issue.

[haydenhancock]

This was resolved by disabling the Virtual Machine Platform Windows feature. Not exactly sure how this got enabled or why it would only affect Windows Server virtual machines but this did allow me start my Windows 2019 server virtual machines.

[scottgus1]

This was resolved by disabling the Virtual Machine Platform Windows feature.

This enables Hyper-V, which can hobble Virtualbox. Running Virtualbox on top of Hyper-V isn't all there yet, but it is making progress.

Often a major Windows Update enables Hyper-V, or one of the services mentioned here: I have a 64bit host, but can't install 64bit guests, posts 2 & 3