vSphere Replication cannot establish a tcp connection to server at 120.0.0.1:8123

You recently updated your vCenter SSL certification. Everything was working great with vSphere replication before you changed the SSL certificate.

You check the /opt/vmware/hms/logs/hms.log and you see errors related to :8123 connections being refused.

Solution: Don’t waste anytime. Just upgrade to 8.3.1

https://kb.vmware.com/s/article/2093139