Oracle manageddataaccess error

See more:

C#

Oracle

hello experts,
unable to solve error, please help me.

Error is : Value cannot be Null. Parameter name key.

code is:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using Oracle.ManagedDataAccess.Client;

namespace OracleManagedDataAccess
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            try
            {
                string lsConStr = "Data Source=(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=xxx.x.xxx.x)(PORT=1521)))(CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=xxxxx)));User Id=xxx;Password=xxx; Pooling = false";
                OracleConnection lobjConn = new OracleConnection(lsConStr);

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

        }
    }
}

What I have tried:

i don't understand what is the actual problem