100% Resolved: VMware vCenter Upgrade Failed 6.7 to 7.0 to 8.0 VMware vCenter upgrade stage 1 and 2 pre-check failed from version 6.7 to 7.0 to 8.0 method invocation [Error 1] Unknown host [Read more] https://hyperhci.com/100-resolved-vmware-vcenter-upgrade-failed-6-7-to-7-0-to-8-0/