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.
