Hi,

I have a WPF app written in C# 3.5

I have created a custom principal and attach it to the thread in my main
window with the following code...

           CustomPrincipal principal = new CustomPrincipal(new
CustomUser(), new string[0]);
           Thread.CurrentPrincipal = principal;

Now, I have the following line in another WPF window to get the custom
principal from the thread to check the user, but I get an error saying I
cannot cast a generic principal to my custom principal (note, if I put this
line straight after the code to set the principal above then it casts the
principal without any problems)

CustomUser user =
(CustomUser)((CustomPrincipal)Thread.CurrentPrincipal).Identity;