Virtual Box VT-x is not available (VERR_VMX_NO_VMX).. Hyper V and core isolation is disabled

Question

I'm running windows 10 enterprise trying to launch a VM in Virtualbox and it fails with the error. "VMMR0_DO_NEM_INIT_VM failed: VERR_NEM_MISSING_KERNEL_API_2 (VERR_NEM_MISSING_KERNEL_API_2). VT-x is not available (VERR_VMX_NO_VMX)."

I have HyperV disabled in windows features and core isolation turned off

I've checked the registry as well and core isolation / memory itegrity is off there. I've also made sure that in group policy settings that virtualization based security is disabled.

My BIOS does have VT-X /VT-D enabled.

I'm currently on Virtual box 6.1.6 but have tried previous versions back to 6.0.12 with no success.

Answer 1

This happens to me from time to time on my Windows 10 host. I tried a lot of things to fix it, but what worked in the end is running this command as an administer in PowerShell:

bcdedit /set hypervisorlaunchtype off 

and rebooting the computer.

Answer 2

I got this error too. I got passed it by uninstalling VirtualBox, removing any residual files, and then reinstalling VirtualBox.

Based on Google search results of this error, posts about it started appearing only a few days ago. I found out how to get passed this error from one of the comments on https://www.reddit.com/r/Windows10/comments/g4hksf/virtualbox_problems/.

By the way, the only Windows feature that needs to be turned off is HyperV.