Configuring the AuthenticationType from the WebUI will now work, just restart and NzbDrone will change the AuthenticationType on start.

NzbDrone/Model/AuthenticationType.cs

@@ -0,0 +1,13 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace NzbDrone.Model
+{
+    public enum AuthenticationType
+    {
+        Anonymous = 0,
+        Windows = 1
+    }
+}