Starting multiple WPF windows from a ribbon addin in Word - error

Hi,

I am running an addin in Word that allows the user to call a WPF window and close it. The user should be able to open another window by clicking the same button again. The following code snippet shows my current implementation of this:

                    MainWindow win = new MainWindow(graph); //create MainWindow object

                    if (System.Windows.Application.Current == null)
                    {
                        System.Windows.Application app = new System.Windows.Application { ShutdownMode = ShutdownMode.OnExplicitShutdown };
                        app.Run(win);

                    }
                    else 
                    {
                        System.Windows.Application.Current.Shutdown();
                        System.Windows.Application app = new System.Windows.Application { ShutdownMode = ShutdownMode.OnExplicitShutdown };
                        app.Run(win);
                    }

Whenever the the user closes the first opened window and tries to open a new one, the following error gets thrown:

Cannot create more than one System.Windows.Application instance in the same AppDomain.

I added the ShutdownMode parameter since I got the error: "The Application object is being shut down" before. However, it seems like the app object is still hanging around preventing me from creating a new window. How can I kill this object for good when detecting that

System.Windows.Application.Current =! null

Alternatively, how I can I run multiple windows using the same app object without getting the "The Application object is being shut down" error?

Any help is greatly appreciated.

Thanks,

Michael