VMware 6.7 PSC Decommission: Failed to get the PSC thumbprint

As part of our recent VMware 6.7 upgrade we where migrating from external PSC to embedded PSC.

All went fine until we tried to decommission the old PSC’s, when trying to view the thumbprint we got the below error:

Failed to get the PSC thumbprint. Ensure PSC port is correct.

With out getting the thumbprint you can’t continue.

We tested accessing the PSC using web browser,

using openssl from the vCenter appliance

openssl s_client -connect PSC01.domain.local:443

We also tested access using telnet to confirm if port 443 was open

curl -v telnet://PSC01.domain.local:443

All test came back fine and there was no ports being blocked.

In the end the issue was caused by using the short name for the vCenter servers https://VCSA/UI

When we changed to the full FQDN, https://VCSA.domain.local/UI this fixed the issue and we where able to complete the decommission. The issue looks to be related to the SAN name on the cert only having the FQDN.