Perhaps you need to try to deploy an earlier version. And if successful, then update it.
thanks for the advice. I downloaded 4.5.1 and at least got it deployed with no error. 4.5.1 does not have that prefer IPv6 field. Both 4.6.1. and 4.5.1 are in the support matrix for my vCenter 6.5U1 but 4.6.1 does not work because it could no handle the newly added field. Maybe Vmware should do better QA before they release software.