When setting up ConfigMgr 2012 R2 to use a remote server to host the Software Update Point on Windows Server 2012 R2, configuration of the SUP may fail. The WCM.log will show entries such as:
Checking for supported version of WSUS (min WSUS 3.0 SP2 + KB2720211 + KB2734608) Checking runtime v2.0.50727... Failed to create assembly name object for Microsoft.UpdateServices.Administration. Error = 0x80131701 Checking runtime v4.0.30319... Did not find supported version of assembly Microsoft.UpdateServices.Administration Supported WSUS version not found Remote configuration failed on WSUS Server
The error implies that WSUS 3.0 SP2 is required for the remote SUP, however it is not for Windows Server 2012 R2. Rather, since the SUP is on a remote server, the WSUS admin console server feature is required to be installed on the primary site server.