Wanted to just put a quick block up incase people have the same issue I had with vCenter upgrade to 6.5 VCSA. It was stalling at 62%. I was showing some weird localhost certificate errors i the logs. So I had a long ticket with VMWare trying to figure it out and eventually we ran the certificate manager on the 6.0u2 Windows host and updated all the vcenter certificates. I had to clean out the temp files it was using becuase it was pulling in some odd data, but once those were clean and generated clean certificates using my host name on them, after a retry it went right through.