WCF Forms Authentication authorization using ASP.NET roles = Access Denied?

I have a basic WPF application where the client writes to a database. I'm using IIS on a server 2012 machine to host the web service. I'm trying to implement Forms authentication, and I have all that working (passing a username and password in the xaml.cs from the client which authenticates my ASP.NET user which works. I then want to implement ASP.NET roles authorization for different commands (Submit Request, Remove Request, etc). The method we're supposed to use is "[PrincipalPermission(SecurityAction.Demand, Role = "Allowed")]"I have a basic WPF application where the client