Nothing happens after UM 3.6.1 attempts to log into vCenter

Hi there,

I have been trying to add a vCenter Server 6.5 onto the Products tab but to no avail. There is an inactive entry that was the vCenter 5.5.

I have used in combination of IP address, FQDN, NetBIOS for the hostname with Domain\Username, username and local admin accounts with known passwords. Does it matter if I didn't define the PSC initially and edit it later? Please could someone help me out on how I can check this in depth?

Thanks in advance!