I'm trying to create a parameter of the type [Microsoft.ActiveDirectory.Management.ADGroup] and another parameter with the type [Selected.Microsoft.ActiveDirectory.Management.ADGroup], which appears to be a PSCustomObject. When I declare that, it works fine. I'm stuck on the [Microsoft.ActiveDirectory.Management.ADGroup] parameter, though. I've tried Add-Type before the function starts, tried Import-ModuleActive Directory, tried the ReflectionAssembly with PartialName. The results are all the same. 'Cannot bind argument to parameter 'MyParameter' because it is null.