Tcp Server stops responding

This is the following I have been watching 2 tutorial of how to do a tcp Server and a tcp Client . I had to follow everything step by step but for some reason when I start the server it stops responding, but when the client connects it from an update shows and a textbox "New Message: Hello From Client". After that only if I connect again is that he responds again but soon after he stops responding. This only happens with the server.

 private void BtnStart_Click(object sender, EventArgs e)
    {
        TcpServerRun();
        Thread tcpserverRunThread = new Thread(new ThreadStart(TcpServerRun));

    }

    private void TcpServerRun()
    {
        TcpListener tcplistener = new TcpListener(IPAddress.Any, Convert.ToInt32(TxtBoxPort.Text));
        tcplistener.Start();
        updateUI("listening");

        while (true)
        {
            TcpClient client = tcplistener.AcceptTcpClient();
            updateUI("Connected");
            Thread tcpHandlerThread = new Thread(new ParameterizedThreadStart(tcpHandler));
            tcpHandlerThread.Start(client);
        }
    }
    private void tcpHandler(object client)
    {
        TcpClient mClient = (TcpClient)client;
        NetworkStream stream = mClient.GetStream();
        byte[] messagem = new byte[1024];
        stream.Read(messagem, 0, messagem.Length);
        updateUI("New Message: " + Encoding.ASCII.GetString(messagem));
        stream.Close();
        mClient.Close();
    }

    private void updateUI(string s)
    {
        Func<int> del = delegate()
        {
            TxtBoxLog.AppendText(s + System.Environment.NewLine);
            return 0;
        };
        Invoke(del);
    }