RDP to Server 2012 and Server 2011 RWW

Connections to Remote Web Workplace at several different locations fail with "The computer has closed the remote desktop session."

Connections configured manually.  Remote locations are all IP Address:Port and access from any WIndows XP, Vista, Win7 and Win8 computer works fine.

All locations have SSL certificates issued by a trusted authority.

Has anyone been able to RDP into a remote web workplace?