XEN 2.0 System.MethodAccessException on Xbox360 at runtime

Oct 13, 2010 at 8:44 PM

hi, I'm getting a System.MethodAccessExceptoion in 

Xen.Ex.Material.ShaderInstance Begin Method

 on:

this.instance.Begin(shaderSystem, !shaderSystem.IsShaderBound(instance), extChanged, ext);

Any idea whats causing it?