While fetching data from Excel to datagridview third Cell data(lname) not displayed on Datagridview..

private void Upload_Excel_click(object sender, EventArgs e)
    {
// For Uploading Excel file From Computer
        int count = 0;
        string[] FilenameName;
        foreach (string item in openFileDialog1.FileNames)
        {
            FilenameName = item.Split('\\');
            File.Copy(item, @"Images\" + FilenameName[FilenameName.Length - 1]);
            count++;
        }
//for storing data from Excel to datagridview
        System.Data.OleDb.OleDbConnection MyConnection;
        System.Data.DataSet DtSet;
        System.Data.OleDb.OleDbDataAdapter MyCommand;
        MyConnection = new System.Data.OleDb.OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source='D:\\Edbeans Windows App Modified\\Edbeans Windows App\\Project\\Registration\\bin\\Debug\\Images\\Book1.xlsx';Extended Properties=\"Excel 12.0 Xml;HDR=YES;IMEX=1\";");
        MyCommand = new System.Data.OleDb.OleDbDataAdapter("select * from [Sheet1$]", MyConnection);
        MyCommand.TableMappings.Add("ams_records ", "temp_reg_details");
        DtSet = new System.Data.DataSet();
        MyCommand.Fill(DtSet);
        dataGridView1.DataSource = DtSet.Tables[0];
        MySqlConnection local_connection = myConnection.getConnection();
        local_connection.Open();
        string str = this.dataGridView1.Rows.Count.ToString();
        int num = int.Parse(str);
        for (int row = 0; row < num - 1; row++)
        {

            string query = "INSERT INTO temp_reg_details(fname, mname, lname, class_code,guard_fname,guard_mname,guard_lname,guard_mob_no,guard_email,rfid_cardNo,rfid_password) VALUES (@fname, @mname, @lname, @class_code, @guard_fname, @guard_mname, @guard_lname, @guard_mob_no, @guard_email, @rfid_cardNo, @rfid_password)";
            MySqlCommand cmd = new MySqlCommand(query, local_connection);
            cmd.Parameters.AddWithValue(
                    "@fname", dataGridView1.Rows[row].Cells[1].Value.ToString());
            cmd.Parameters.AddWithValue(
                "@mname", dataGridView1.Rows[row].Cells[2].Value.ToString());
//Its shows error of NullrefereceException was unhandled(Object reference not set to an instance of an object.) while fetching data from 3rd cell
            cmd.Parameters.AddWithValue(
                 "@lname", dataGridView1.Rows[row].Cells[3].Value.ToString());
//below are working fine
            cmd.Parameters.AddWithValue(
                "@class_code", dataGridView1.Rows[row].Cells[4].Value.ToString());
            cmd.Parameters.AddWithValue(
               "@guard_fname", dataGridView1.Rows[row].Cells[5].Value.ToString());
            cmd.Parameters.AddWithValue(
               "@guard_mname", dataGridView1.Rows[row].Cells[6].Value.ToString());
            cmd.Parameters.AddWithValue(
               "@guard_lname", dataGridView1.Rows[row].Cells[7].Value.ToString());
            cmd.Parameters.AddWithValue(
               "@guard_mob_no", dataGridView1.Rows[row].Cells[8].Value.ToString());
            cmd.Parameters.AddWithValue(
               "@guard_email", dataGridView1.Rows[row].Cells[9].Value.ToString());
            cmd.Parameters.AddWithValue(
               "@rfid_cardNo", dataGridView1.Rows[row].Cells[10].Value.ToString());
            cmd.Parameters.AddWithValue(
               "@rfid_password", dataGridView1.Rows[row].Cells[11].Value.ToString());
            cmd.ExecuteNonQuery();
            cmd.Parameters.Clear(); //for proper looping 
        }
        MessageBox.Show("sucess");
        local_connection.Close();

    }