Issue in CRM demo:Add a Login Module

[Wan]

Hi
I downloaded the demo a few days ago, wanna add a "login module" in the project.
The system there is always an exception, after startup!

UnhandledException:

private void Application_UnhandledException(object sender, ApplicationUnhandledExceptionEventArgs e)
        {
            // If the app is running outside of the debugger then report the exception using
            // the browser's exception mechanism. On IE this will display it a yellow alert
            // icon in the status bar and Firefox will display a script error.
            //System.Diagnostics.Debug.WriteLine(Microsoft.Practices.Prism.ExceptionExtensions.GetRootException(e.ExceptionObject).Message);
            System.Diagnostics.Debug.WriteLine(Microsoft.Practices.Prism.ExceptionExtensions.GetRootException(e.ExceptionObject).InnerException.Message);
            if (!System.Diagnostics.Debugger.IsAttached)
            {

                // NOTE: This will allow the application to continue running after an exception has been thrown
                // but not handled.
                // For production applications this error handling should be replaced with something that will
                // report the error to the website and stop the application.
                e.Handled = true;
                Deployment.Current.Dispatcher.BeginInvoke(delegate { ReportErrorToDOM(e); });
            }
        }

exception details:

Unhandled Error in Silverlight Application
Code: 4004
Category: ManagedRuntimeError
Message: Microsoft.Practices.Prism.Modularity.ModuleInitializeException: An exception occurred while initializing module 'LoginModule'.
    - The exception message was: The composition remains unchanged. The changes were rejected because of the following error(s): The composition produced multiple composition errors, with 24 root causes. The root causes are provided below. Review the CompositionException.Errors property for more detailed information.

Please help

Li