Recently I was upgrading a vCenter 6.0 U2 to 6.5, and after successfully upgrading the external PSC, the process failed at the vCenter. After some troubleshooting, I found out that I needed to add the user to the “Replace a Process Level Token” attribute under the Local Security Policy. You can find the Microsoft documentation… Continue reading vSphere Upgrade 6.0 to 6.5 Fails with Replace Process Level Token error.