Events Not Triggering C#

I am working on Emotiv on a C# WPF Project but the event engine_UserAdded is not triggering. It works fine on the example code though but just didn’t work on my project. Any ideas why is this so? Does it not plays well with WPF Project?

public MainWindow()
        {
            InitializeComponent();
        }

        private void frmMain_Initialized(object sender, EventArgs e)
        {
            engine = EmoEngine.Instance;
            engine.EmoEngineConnected += new EmoEngine.EmoEngineConnectedEventHandler(EmoEngineConnectedEvent);
            engine.UserAdded += new EmoEngine.UserAddedEventHandler(engine_UserAdded);
            engine.EmoEngineDisconnected += new EmoEngine.EmoEngineDisconnectedEventHandler(EmoEngineDisconnectedEvent);
            engine.Connect();
        }

        void EmoEngineConnectedEvent(object sender, EmoEngineEventArgs e)
        {
            MessageBox.Show("Connected");
        }

        void EmoEngineDisconnectedEvent(object sender, EmoEngineEventArgs e)
        {
            MessageBox.Show("Disonnected");
        }

        void engine_UserAdded(object sender, EmoEngineEventArgs e)
        {
            MessageBox.Show("User added");
        }