vCenter HA first launched with vSphere 6.5 for the vCenter Server Appliance and it was configured using the Flash based vSphere Web Client.
With vSphere 6.7 U1 you can now configure vCenter HA, much more easily, using the HTML5 based vSphere Client.
You no longer have to decide between “Basic” or “Advanced” setup methods. There is only one process, no matter where your vCenter Server Appliance resides.
Simply navigate to vCenter Server > Configure > vCenter HA > SET UP VCENTER HA
Select the virtual machine network port group you wish to use for the vCenter HA network, define what compute and storage you want the Passive and Witness VMs to reside on and click Next
Provide the vCenter HA network IP details for all three nodes and click Finish
That is all there is to it. After a few short minutes, the Passive and Witness will be cloned from the vCenter Server Appliance, customised to use their unique vCenter HA IP addresses and configured for vCenter HA
If your vCenter Server Appliance is not a virtual machine that is managed by itself, the only additional step you will have to perform is to provide the credentials of the managing vCenter Server and rest is handled the same. No more manual cloning or customising.
have you tried reinstalling? 