Can't enable cluster EVC - "Powered-on or suspended virtual machines on the host may be using CPU features hidden by that mode"

Products

• VMware vCenter Server
• VMware vSAN 8.x
• VMware vSAN 7.x
• VMware vSAN 6.x
• VMware vSAN

Issue/Introduction

• The following error message is observed when attempting to enable EVC at the cluster level.

The host cannot be admitted to the cluster's current Enhanced vMotion Compatibility mode. Powered-on or suspended virtual machines on the host may be using CPU features hidden by that mode

Environment

• vCenter 8.x
• vCenter 7.x

Cause

• Per-VM EVC may cause issues with enabling cluster level EVC. When attempting to enable cluster level EVC it will point out which hosts contain VMs which are preventing the operation.
• On clusters where the vCenter is running on that cluster, the existence of a powered on vCenter on that cluster will prevent enabling of EVC. 

Resolution

• Power off and disable per-VM EVC on VMs that the cluster is calling issues with.
  
  
• For clusters that the vCenter VM is a part of, you must create a new cluster with EVC enabled first, then migrate VM's to that new cluster.  Please see steps in KB: Enable EVC in vCenter Server 6.5/6.7/7.0/8.0 if VC VM is part of the same cluster
  
  
  • CAUTION: If this is a vSAN cluster, see this KB for the correct procedure:  How to enable EVC in vCenter Server 6.5/6.7/7.0/8.0 if VC VM is part of the same vSAN cluster