ERROR: additional information: only one usage of each socket address (protocol/network address/port) is normally permitted

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C#

client-server

I'am working on WinSock Sockets Programming with C#. I'm basically making a Client/Server application sending an data between client and the server. I'm using winsock control in c#.

I get the error when I try sending an data between client and the server. My server listens for connections on port 514,

server

using System;
using System.Collections.Generic;
using System.Windows.Forms;
using System.Net;
using System.Threading;
using System.Net.Sockets;

namespace server
{
    public partial class Form1 : Form
    {      
        public Form1()
        {
            InitializeComponent();        
        }
        const string DEFAULT_SERVER = "xx.x.xx.xxx";
        const int DEFAULT_PORT = 514;

        System.Net.Sockets.Socket serverSocket;
        System.Net.Sockets.SocketInformation serverSocketInfo;
        private void Form1_Load(object sender, EventArgs e)
        {
           

        }
        public string Startup()
        {
           
            IPHostEntry hostInfo = Dns.GetHostByName(DEFAULT_SERVER);
            IPAddress serverAddr = hostInfo.AddressList[0];
            var serverEndPoint = new IPEndPoint(serverAddr, DEFAULT_PORT);            
            serverSocket = new System.Net.Sockets.Socket(System.Net.Sockets.AddressFamily.InterNetwork, System.Net.Sockets.SocketType.Stream, System.Net.Sockets.ProtocolType.Tcp);
            serverSocket.Bind(serverEndPoint);
            return serverSocket.LocalEndPoint.ToString();
        }

        public string Listen()
        {
            int backlog = 0;
            try
            {
                serverSocket.Listen(backlog);
                return "Server listening";
            }
            catch (Exception ex)
            {
                return "Failed to listen" + ex.ToString();
            }
        }
        public string ReceiveData()
        {
            System.Net.Sockets.Socket receiveSocket;
            byte[] buffer = new byte[256];

            receiveSocket = serverSocket.Accept();

            var bytesrecd = receiveSocket.Receive(buffer);

            receiveSocket.Close();

            System.Text.Encoding encoding = System.Text.Encoding.UTF8;

            return encoding.GetString(buffer);
        }
       

        private void button1_Click(object sender, EventArgs e)
        {
            string serverInfo = Startup();
            textBox1.Text = "Server started at:" + serverInfo;

            serverInfo = Listen();
            textBox1.Text = serverInfo;
            
            serverInfo = ReceiveData();
            textBox1.Text = serverInfo;

        }

        private void wsa_DataArrival(object sender, AxMSWinsockLib.DMSWinsockControlEvents_DataArrivalEvent e)
        {
            ReceiveData();
            Listen();
        }

        private void wsa_ConnectEvent(object sender, EventArgs e)
        {
            Listen();
        }
    }
}

Client

using System;
using System.Net.Sockets;
using System.Threading;
using System.Windows.Forms;

namespace CLIENT
{
    public partial class Form1 : Form
    {
public Form1()
        {
            InitializeComponent();
        }
       Boolean isConnect= false;
private void btnConnect_Click(object sender,EventArgs e)
{
    try
    {
        win.Close();

       
        win.Connect(txtIP.Text, txtPort.Text);

    }
   
    catch (System.Windows.Forms.AxHost.InvalidActiveXStateException g)
    { 
        txtdata.Text += "\n" + g.ToString(); 
    }
}

private void btnSend_Click(object sender, EventArgs e)
{
    try
    {
        if (isConnect)
        {          
            win.txtsenddata(txtdata.Text);          
            DataInput.Text += "\nClent(Client:) : " + txtdata.Text;   
            txtsenddata.Text = "";
        }
        else
            MessageBox.Show("You are not connect to any host ");
    }
    catch (AxMSWinsockLib.AxWinsock.InvalidActiveXStateException g)
    {
        txtdata.Text += "\n" + g.ToString(); 
    }
    catch (Exception ex) 
    { 
        txtdata.Text +="\n" + ex.Message; 
    }
}

void win_Error(object sender, AxMSWinsockLib.DMSWinsockControlEvents_ErrorEvent e)
{
    txtdata.Text += "\n- Error : " + e.description;
    isConnect = false;
}

private void win_DataArrival(object sender, AxMSWinsockLib.DMSWinsockControlEvents_DataArrivalEvent e)
{

    String data ="";

    Object dat = (object)data;
    w1.GetData(ref dat);

    data = (String)dat;


    txtdata.Text += "\nServer - " + w1.RemoteHostIP + " : " + data ;

}


private void win_ConnectEvent(object sender, EventArgs e)
{   
    txtdata.Text += "\n - Connect Event : " + w1.RemoteHostIP;


    isConnect = true;
}

It workes 1st time correctly but in second time it gives me an error

An unhandled exception of type 'System.Net.Sockets.SocketException' occurred in System.dll  Additional information: Only one usage of each socket address (protocol/network address/port) is normally permitted

someone help me to solve my problem please.

What I have tried:

I'm trying to get the data from the client to server on many times but it worker only one time on second time it gives me an error An unhandled exception of type 'System.Net.Sockets.SocketException' occurred in System.dll Additional information: Only one usage of each socket address (protocol/network address/port) is normally permitted on the line in the server program

serverSocket.Bind(serverEndPoint);