(this is on the latest version of vCenter 6.7)
I had to re-install vCenter which I did with the same FQDN and IP address.
When I try to connect via Safari I get the message 'Safari can't open the page "FQDN" because Safari can't establish a secure connection to the server "FQDN"
I can connect via Firefox and Chrome just fine. I have cleared cache, cookies, history and still didn't work.
Last time I had this problem I had to completely re-install my Mac. Surely there must be an easier solution.