During the deployment of a VCF environment with an existing vCenter Server (converge), the validation checks fail on the "existing components" section.
/var/log/vmware/vcf/domainmanager/domainmanager.log contains:
Error occurred while getting certificate chain for 'vcenter.example.com'java.net.NoRouteToHostException: No route to host
VCF 9.0
This can be caused by multiple DNS entries (A records) for the vCenter Server.
Correct the entries in DNS to use a single A record for the vCenter.