I got kicked in the face by this again, and I even had the resolution documented internally. Lost 45 minutes looking through logs before I finally search VMware KB for it. Argv!
Unexpected exception: converter.fault.clonefault
(converter.fault.CloneFault) {
dynamicType = ,
faultCause = (vmodl.MethodFault) null,
description = Unknown exception,
msg = ,
This is caused by the source computer not being able to communicate with the ESX server by DNS resolution. Simply added the DNS entry into c:windowssystem32etchosts and I was good to go.
VMware’s KB on this: http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1034292