I am getting this error(I am using Oracle.DataAccess dll):

```
{Oracle.DataAccess.Client.OracleConnection}

(Oracle.DataAccess.Client.OracleException).DataSource threw an exception of type 'System.NullReferenceException'

```

StackTrace :

```
at Oracle.DataAccess.Client.OracleException.HandleErrorHelper(Int32
errCode, OracleConnection conn, IntPtr opsErrCtx, OpoSqlValCtx*
pOpoSqlValCtx, Object src, String procedure, Boolean bCheck, Int32
isRecoverable)
   at Oracle.DataAccess.Client.OracleException.HandleError(Int32 errCode,
OracleConnection conn, IntPtr opsErrCtx, Object src)
   at Oracle.DataAccess.Client.OracleConnection.Open()

```

Code:

```
 using (OracleConnection conn = new OracleConnection(ConfigurationManager.ConnectionStrings["myConnection"].ConnectionString))
            {
                using (OracleCommand cmd = conn.CreateCommand())
                {
                    cmd.CommandText = "<<Procedure Name>>";
                    cmd.Parameters.Add("v_cur", OracleDbType.RefCursor).Direction = ParameterDirection.Output;

                    conn.Open(); --line throws exception
                    using (OracleDataReader reader = cmd.ExecuteReader())
                    {
                        while (reader.Read())
                        {
                            retVal = reader["VALUE"].ToString();
                        }
                        reader.Close();
                    }
                }
            }

```

Any inputs will be helpful? thanks.