After Windows update 2020 may build 2004, vmvare doesnt support Virtualize intel Vt-x/EPT. How fix this problem. I update vmvare to 15.5.5, But it didn`t help
I recently had some issues with my laptop that required Lenovo remoting in and molesting settings and ultimately resetting things. Once again I ran into the nested virtualization not supported error. At this point, I am pretty well practiced in this **bleep** of an error. Went into windows 10 features and turned off "Virtual Machine Platform", rebooted and viola, it works again.
SInce I had to reboot anyway, I went ahead and made sure Intel VT-x was enabled in the BIOS.
I also made sure of my VM engine settings.
I know the original post is old but I had this exact issue today. I tried all the things listed like the power shell edit, rebooting, uninstalling/reinstalling etc. My fix doesn't seem to be listed so I'll add in case it can help someone down the road. I noticed the device security exclamation point one day in windows defender (see pics) and went in and turned it on. A day or two later I tried to open Cisco CML2 (nested VM) and even tried just a normal linux VM and all failed. The nested CML2 VM had the same error as the original poster and the linux non-nested VMs had a different error, something about authorization. Long story short I turned memory integrity off, rebooted and all my VMs started working. Just to test I turned it back on and it killed all VMs again. This was the fix for me.
Windows 11 Build 10.0.22000
All VMs were Ubuntu based but I don't think it matters.
The post is old, but maybe this will help someone,
The problem in my case is I installed the Sandbox feature in my windows so this feature takes that VM interface, when I disable it, it works normally again
Despite the age of this thread, this issue continues to present itself for me. Running Windows 11 Enterprise 22H2 on a Dell Precision 3650 (i7-11700, 48GB RAM), have had the issue with Workstation Pro 15 and 16 and with previous versions of Windows 11 and 10.
I can never guarantee a patch, or a BIOS update won't change some security feature and end up causing this issue. It's getting fairly frustrating that I have to waste 30-45 minutes every time this happens to troubleshoot. While Workstation is a better platform, this issue is the one thing that continues to make me want to say "I'll just use HyperV, forget this" and be done.
I used BCDEDIT today, and removed the Virtual Machine Platform from Windows (somehow installed again), and I'm still not getting into my VMs. Error about side channel mitigations enabled. Followed by "would I like to disable VT-X/EP-T". Followed by failing even if I disable because nested virtualization isn't supported.
You can try with steps mentioned by me in my last reply :-
Please update me in case this help you get resolve your problem
I have done all of the recommendations and periodically find after reboot that VBS is running again. The only thing I've been able to do after VBS is magically re-enabled is to use Microsoft's DG Readiness tool to re-disable VBS;
To Disable DG/CG.
Usage: DG_Readiness.ps1 -Disable
I downloaded the latest version Readiness Tool Version 3.6 Release.