Problem with using service from process which started it...

Hi everyone,

I have a problem using callbacks and WCF.
I'm trying to write a service for message logging. Imagine several processes which want to write into one
"global" logfile. I have a project called "LogMessageServiceApplication". This is basically a WPF-Application
with an UI that displays all recently added messages. This application also starts the service in the background.
Using the service from other processes to write messages works fine.
But If I want to subscribe a callback from "LogMessageServiceApplication" the program freezes and crashes eventually.
Are there any restrictions with services from the process which actually started the service?
For better understanding see code snippet below

        public MainWindow()
        {
            InitializeComponent();
            StartService();
            SetCallback();
            Hide();
        }
   

        private void StartService()
        {
            string serviceName = "net.tcp://localhost:12500/dSPACELogMessageService";
            serviceHostConnection = new ServiceHost(typeof(MessageService), new Uri(serviceName));
            serviceHostConnection.Open();  // Starting the service here works fine
        }

        private void SetCallback()
        {
            LogMessageServiceCallback callback = new LogMessageServiceCallback(_logHandler);
            DuplexChannelFactory duplexChannelFactory =
                new DuplexChannelFactory(callback, new NetTcpBinding(), new EndpointAddress(
                                                                      "net.tcp://localhost:12500/dSPACELogMessageService"));
            _proxy = duplexChannelFactory.CreateChannel();
            _proxy.Subscribe(); // This is the line of code where the program freezes :-(
        }

Is it forbidden to use the service from the process which started it ?

I appreciate any help or information.

Best Regards,
Simon