This appears broken in vSphere 6.0U1 or something…
See this post on reddit. https://www.reddit.com/r/vmware/comments/3n0rl9/issues_with_vcsa_migration_fling/
http://imgur.com/pqquI5n
vcenter 6 on win 2008r2, external SQL server. It fails when trying to query inventory service registry keys.