Hi Matrix,
First lets clarity the situation:
1. Certificates used to secure the SSL communication between VCOps and VC are not related in any way to the VCOps license. This means the VCOps license (and the fact it is not licensed right now) should prevent you from registering additional VCs.
2. The problem with the certificates should be with VCs certificate. Actually VCOps connects to VC by using VC's certificate to establish SSL connection. You are saying that VC certificate is OK, but try to double check that.
I would advice you to do the following:
1. Post the exact error message you are receiving in the UI.
2. Take a look at /var/log/vmware/admin.log and post the relevant error message.
3. Post VC certificate's details.
Those 3 items will help us to troubleshoot further and give suggestions.
Thanks,
Alex D.