VMware vCenter – error while upgrading VCSA 6.7 to 7.0 (Unknown host) on stage 2

VMware vCenter – error while upgrading VCSA 6.7 to 7.0 (Unknown host) on stage 2

i just started updating routine with customer vmware infrastructure, he had a VCSA 6.7.0.52000 and i updating to 7.0.3-20150588. On the stage 2 of upgrading vcenter i had an error message „Pre-upgrade check failed due the following problem: Error in method invocation [Errno 1] Unknown host„

I resolved it by replacing the IP address with FQDN of VCSA and ESXi host FQDN in the first page of stage 2 upgrade wizzard and now ugprade working fine ! .)