I know there have been several posts about this issue, however, I have tried all the solutions and none seem to be working for me. I had the VPN client working on this system (Surface w/ Windows 8.1 Pro) yesterday. Today after installing Microsoft Office 2010 Professional Plus w/ service pack 1, I receive an Error 51: Unable to communicate with the VPN subsystem. I uninstalled Office and tried to connect and got the same error.
I will attempt to uninstall and re-install the client and see if that works, but am trying to see if anyone else has seen this issue and if so, is there a fix for it.
I need to get this system to a user today, with or without MS Office, but would like them to be able to have a fully functioning system when they come back.