metoda asynchroniczna wyrzuca błąd

       while (true)          
       {       
                   //Byte[] data = server.Receive(ref remote);                 
                    try
                    {
                        IAsyncResult aresult = server.BeginReceive(new AsyncCallback(polaczenie), null);
                    }
                    catch (Exception ex)
                    {
                        MessageBox.Show(ex.ToString());

                    }              

        }

        class UdpState
        {
            public IPEndPoint e;
            public UdpClient u;
        }
        private void EndReceive(IAsyncResult result)
        {
            UdpClient u = (UdpClient)((UdpState)(result.AsyncState)).u;
            IPEndPoint e = (IPEndPoint)((UdpState)(result.AsyncState)).e;
            byte[] ode = u.EndReceive(result, ref e);
            string info = Encoding.ASCII.GetString(ode);
            SetText(e.Address.ToString() + "  " + e.Port.ToString());
            while (!result.IsCompleted)
            {
                Thread.Sleep(200);
            }
            
            u.BeginReceive(new AsyncCallback(EndReceive), new UdpState() { e = e, u = u });

        } 

Ten kod wyrzuca błąd 0x80004005. A jak zabiorę linijkę:

 MessageBox.Show(ex.ToString()); 

to program nie wyrzuca błędu, ale automatycznie się zamyka. Co robię źle?

Edit1:
Jak dam:

   while (true)
                {  
                                      
                             
                    try
                    { 
                        server = new UdpClient();                      
                        remote = new IPEndPoint(IPAddress.Any, 18900);
                        server.Client.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, true);
                        server.Client.Bind(remote);
                
                        IAsyncResult aresult = server.BeginReceive(new AsyncCallback(EndReceive), new UdpState() { e = remote, u = server });
                          
                    }
                    catch (Exception ex)
                    {
                        MessageBox.Show(ex.ToString());

                    }
                 

                } 

to działa,ale po chwili ram jest zapchany i komputer muli.