Windows – Missing rasgreeng.dll on VPN server when client attempts to connect

I am running into problems setting up a VPN server on Windows 10 Home Anniversary Edition, which 'ver' reports as:

Microsoft Windows [Version 10.0.14393]

I am following the guide at: http://pureinfotech.com/setup-vpn-server-windows-10/

I have configured the server, and when the client attempts to connect, credentials are requested. The connection is immediately dropped after the correct credentials have been input, however.

From the server end the event logs show two errors relating to the connection. The first is the report that rasgreeng.dll could not be initialised:

Remote Access Connection Manager failed to start because the Protocol engine [rasgreeng.dll] failed to initialize. The specified module could not be found.

This is followed by the second, which indicates that IKEv2 failed to initialise:

Remote Access Connection Manager failed to start because the Protocol engine [IKEv2] failed to initialize. The request is not supported.

The rasgreeng.dll is expected under \Windows\System32, but is not available anywhere on the machine. I have also checked on a machine running Windows 10 Home November 2015, but with no luck. I have seen references to this DLL available as a KB patch to add Generic Routing Encapsulation to Windows 8, 8.1, and Server 2008 R2. But my understanding is that this is incorporated into Windows 10.

I have configured the router to avoid handling VPN connections and to pass through VPN requests to the server in question. The firewall configuration on the server appears correct. I have also tried setting the host in a DMZ, but with the same effect.

I am operating under the assumption that it is possible to configure a VPN Server on vanilla Windows 10 Home. Why is the OS attempting to use a non-existent DLL when the client connects? Are these errors a red herring?