Problem 'System.FormatException' in mscorlib.dll

I'm struggling to get this to work.

I have 2 errors coming up,

Exception thrown: 'System.Net.Sockets.SocketException' in System.dll

Exception thrown: 'System.FormatException' in mscorlib.dll

Any help will be greatly appreciated! (Iv'e read other posts and they don't seem to help)

This is the error message:

    public Socket_Chat()
    {
        InitializeComponent();

        // Initialize Component Methods using the variable sck.
        // From the socket fucntion it takes 3 arguments and gives them a type.
        sck = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
        sck.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, true);

        // Setting the client variables for the IP Addresses
        textLocalIP.Text = GetLocalIP();
        textFriendIP.Text = GetLocalIP();
    }

    // Creation of a new method to get IP off host
    // This will automatically get the Local IP for the IP text Boxes so the user won't need to manually enter the IP.
    private string GetLocalIP()
    {
        IPHostEntry host;
        host = Dns.GetHostEntry(Dns.GetHostName());

        foreach (IPAddress ip in host.AddressList)
        {
            if (ip.AddressFamily == AddressFamily.InterNetwork)
            {
                return ip.ToString();
            }
        }

        // Else returns my local host IP address
        return "127.0.0.1";
    }

    private void MessageCallBack(IAsyncResult aResult)
    {
        try
        {
            int size = sck.EndReceiveFrom(aResult, ref epRemote);
            if (size > 0)
            {
                byte[] recieveData = new byte[1464];

                receivedData = (byte[])aResult.AsyncState;

                ASCIIEncoding eEncoding = new ASCIIEncoding();
                string receivedMessage = eEncoding.GetString(receivedData);

                listMessage.Items.Add("Friend: "+receivedMessage);
            }

            byte[] buffer = new byte[1500];
            sck.BeginReceiveFrom(buffer, 0, buffer.Length, SocketFlags.None, ref epRemote, new AsyncCallback(MessageCallBack), buffer);


        }
        catch (Exception exp)
        {
            MessageBox.Show(exp.ToString());
        }
    }

    private void button1_Click(object sender, EventArgs e)
    {
        Programz test = new Programz();
        test.Show();
        Visible = false;
    }

    private void groupBox2_Enter(object sender, EventArgs e)
    {

    }

    private void button2_Click(object sender, EventArgs e)
    {
        try
        {
            epLocal = new IPEndPoint(IPAddress.Parse(textLocalIP.Text), Convert.ToInt32(textLocalPort.Text));
            sck.Bind(epLocal);

            epRemote = new IPEndPoint(IPAddress.Parse(textFriendIP.Text), Convert.ToInt32(textFriendPort.Text));
            sck.Bind(epRemote);

            byte[] buffer = new byte[1500];
            sck.BeginReceiveFrom(buffer, 0, buffer.Length, SocketFlags.None, ref epRemote, new AsyncCallback(MessageCallBack), buffer);

            button2.Text = "Connected";
            button2.Enabled = false;

            button3.Enabled = true;
            // Sets the focus on the message box
            textMessage.Focus();

        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.ToString());
        }
    }

    private void button3_Click(object sender, EventArgs e)
    {
        try
        {
            System.Text.ASCIIEncoding enc = new System.Text.ASCIIEncoding();
            byte[] msg = new byte[1500];
            msg = enc.GetBytes(textMessage.Text);

            sck.Send(msg);
            // Shows the message that I am sending
            listMessage.Items.Add("You"+ textMessage.Text);
            // Clears the text message
            textMessage.Clear();

        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.ToString());
        }
    }

    private void Socket_Chat_Load(object sender, EventArgs e)
    {

    }
}

}

Edit: And now this error comes up:

This is what comes up when I debug:

'WindowsFormsApp2.exe' (CLR v4.0.30319: WindowsFormsApp2.exe): Loaded 'C:\WINDOWS\Microsoft.Net\assembly\GAC_MSIL\System.Management\v4.0_4.0.0.0__b03f5f7f11d50a3a\System.Management.dll'. Skipped loading symbols. Module is optimized and the debugger option 'Just My Code' is enabled.

The thread 0x3b38 has exited with code 0 (0x0). 'WindowsFormsApp2.exe' (CLR v4.0.30319: WindowsFormsApp2.exe): Loaded 'C:\WINDOWS\Microsoft.Net\assembly\GAC_MSIL\System.Numerics\v4.0_4.0.0.0__b77a5c561934e089\System.Numerics.dll'. Skipped loading symbols. Module is optimized and the debugger option 'Just My Code' is enabled. Exception thrown: 'System.ArgumentNullException' in System.dll The program '[14928] WindowsFormsApp2.exe' has exited with code -1 (0xffffffff).