vCenter Server Preupgrade check result error:
VMDir Replication between partners is not working.
Make sure vmdir service is reachable and started in partner nodes and this node before continuing.
VMware vCenter Server 6.7, 7.0 and 8.0
A replication partner stale entry in the vCenter DB:
A command to check a stale entry from the impacted vCenter: /usr/lib/vmware-vmdir/bin/vdcrepadmin -f showpartnerstatus -h localhost -u administrator -w '<passwords>'
This is due to the partner vCenter being powered off if it was decommissioned or maybe reinstalled as standalone without being removed from the Link mode.
To resolve the issue, please contact Broadcom Technical Support to have a live call with the customer to properly resolve this issue.
if the current vCenter is not linked to another vCenter, use the cmsso-util command to unregister the stale vCenter: