Unable to enable Fault Tolerance on a Windows Server 2022 or 2025 VM when VBS is enabled

Products

• VMware vCenter Server

Issue/Introduction

When attempting to enable Fault Tolerance (FT) on a Windows Server 2022 or Server 2025 VM, the following error message may be displayed in the vSphere Client:

Invalid Virtual Machine Configuration

The following entry (or similar) may be found in var/run/log/hostd.log on the ESXi host:

YYYY-MM-DDTHH:MM:SS.744Z verbose hostd[999999] [Originator@6789 sub=Vmsvc.vm:/vmfs/volumes/datastore/FT_VM/FT_VM.vmx opID=qb-111111:h5ui-getData:com.vmware.vsphere.client.vm.impl.FtDatastoresInfo:1111111111:rel-01:VmPropertyProvider:4542587-2xbu6-h5:73459051-97-46-efd8 user=vpxuser:VSPHERE.LOCAL\admin] QueryFTCompatibility: VM is FT compatible: false

Environment

vSphere 7 or 8
Windows Server 2022 or 2025

Cause

While the VM may satisfy all other Fault Tolerance requirements, the following entry in the VM's VMX file will prevent FT from being enabled:

vhv.enabled = "TRUE"

This setting is added to the .VMX file if the box "Enable Windows Virtualization Based Security" was checked at the creation of the VM or enabled later through Edit Settings > VM Options. 

Nested virtualization is not supported with FT VMs.

Resolution

Power off the VM and remove the entry from the VMX file then reattempt to enable FT on the VM, by following the steps below

Log in to the Vsphere client , locate the specific virtual machine (VM) ,right-click on the VM and select Power Off or Shut Down Guest OS. Ensure the VM is fully powered off before proceeding.

 1)Access the VMX File:

•  Navigate to the datastore or directory where the VM's files are stored.
•  Access the VM Directory and Locate the .vmx file associated with the virtual machine.

  cd /vmfs/volumes/vm_datastore/vm_name

 3)Identify the entry in vmx file, by running command:

     cat xxxx.vmx

          cat vm_name.vmx | grep  'vhv.enabled' 

 4)Back up the vmx file

cp vm_name.vmx vm_name.vmx.bak

 5)Remove the Entry:

    vhv.enabled = "TRUE",  from the .vmx file.

 6) Save the changes , After making changes to .vmx file re-enable FT on the VM and check again.

Additional Information

FAQ: VMware Fault Tolerance