I have followed the tutorial "SRCDS Non-Steam Windows (SteamPipe)" and it has been tested and working with multiple WAN players. Unfortunately when I try and add it to the masterlist, this is the error I recieve:
[Sun Aug 18 05:51:00 2013]: Verifying 97.92.39.81:27015 (97.92.39.81:27015) [Sun Aug 18 05:51:00 2013]: Got KEY (cssbeta) from 97.92.39.81:27015 [Sun Aug 18 05:51:00 2013]: Server reply: 90000GameUI_ServerRejectNewProtocol [Sun Aug 18 05:51:00 2013]: FAIL. Server denied me.
I have tried revEMU & GreenLuma; both still give me the same error.