In this video I have performed live upgrade of vCenter Server from 7.x to 8.x. I also hit the issue outlined in this article: https://communities.vmware.com/t5/vSphere-Upgrade-Install/VCSA-upgrade-6-7-to-7-0-fails-on-Stage-2-step-1-at-50-with-quot/td-p/2868120 – “Unable to authenticate user”