1. You cannot Open Site Recovery from vCenter as its grayed out
2. vSphere Replication or Site Recovery Manager plugin in vCenter shows Not accessible
VMware vSphere Replication 9.x
VMware Live Site Recovery 9.x
1. This occurs when the appliance certificate is issued to 'unknown' rather than a valid certificate. The certificate may appear as 'unknown' if it has been upgraded from version 8.2.
2. This occurs when the appliance certificate is issued to a short name instead of the fully qualified domain name (FQDN).
Refer to Site Recovery Manager or vSphere Replication Plugin shows not accessible in vCenter (393317) for solution.