Error while call WhenCalled on GUI-Issues

Hallo,

we have upgraded to Typemock 7.4.0.0 after doing this some of our tests crashed. Most of them are related to remove the "LoadView"-methods. (WPF)
We get the following error (german):
System.Reflection.TargetInvocationException : Ein Aufrufziel hat einen Ausnahmefehler verursacht.
----> System.TypeInitializationException : Der Typeninitialisierer für "<Module>" hat eine Ausnahme verursacht.
----> <CrtImplementationDetails>.ModuleLoadException : The C++ module failed to load during appdomain initialization.

----> System.NullReferenceException : Der Objektverweis wurde nicht auf eine Objektinstanz festgelegt.

Exception has been thrown by the target of an invocation.

Its easy to reproduce:

Class1 (access the view)

    public class Class1
    {
        private MainWindow window;

        public void LoadView()
        {
            window = new MainWindow();
        }

        public void BlaBla()
        {
            LoadView();

        }
    }

TestClass:

    [TestFixture]
    public class TestClass
    {
        [Test]
        public void XX()
        {
            var q = new WpfApplication3.Class1();
            Isolate.WhenCalled(() => q.LoadView()).IgnoreCall(); //crash!

            q.BlaBla();

        }
    }

Hope somebody can help me. Thank you!