I have a pfSense Firewall with OpenVPN against RADIUS Server configured in a Windows Server 2008 R2.
The RADIUS server is configured in pfSense, but when I try the Authentication (Diagnostics -> Authentication) I always get an Authentication Failed error.
In Windows event viewer I get a message, identifying correctly the user trying to log (domain\user), but saying "Code 16, User does not exist or incorrect password". I've tried with a couple of users, one of them Administrator.
The network policy says any user in the domain can log. I have no idea to keep trying. Any hint?
Did you try rebooting the Windows Server?