If you use NetScaler you will want to see these guides. The NetScaler How To Guides show administrators how to get NetScaler up and configured by providing instructions for common scenarios and some not so common ones.
This is in the system event log The connection was prevented because of a policy configured on your RAS/VPN server. Specifically, the authentication method used by the server to verify your username and password may not match the authentication method configured in your connection profile. Please contact the Administrator of the RAS server and notify them of this error