Updating table in C# project causing crash

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using Steema.TeeChart;
using Steema.TeeChart.Styles;
using System.Windows.Forms;
using NativeExcel;

namespace SensorLog
{
  public class Log
   {
    private TChart _chart;
    private DataGridView _list;
    private DataTable _table = new DataTable("EngineeringData");
    private string _logFile;
    private long _recs = 0;
    private int _logs = 0;
    private IWorkbook book;
    private IWorksheet sheet;


    public Log(TChart chart, DataGridView list)
    {
        _chart = chart;
        _list = list;
        _list.DataSource = _table;
        MakeTable();
        book = Factory.CreateWorkbook();

        _logFile = "Log_"
            + DateTime.Now.Year.ToString()
            + "-"
            + DateTime.Now.Month.ToString()
            + "-"
            + DateTime.Now.Day.ToString()
            + "_"
            + DateTime.Now.Hour.ToString()
            + "-"
            + DateTime.Now.Minute.ToString()
            + "_.xls";
    }

    public void Start()
    {
        _table.Clear();
        _recs = 0;

        sheet = book.Worksheets.Add();

        AnalogSensor.NewAnalogSensorData
            += new EventHandler<AnalogSensorDataEventArgs>(AnalogSensor_NewAnalogSensorData);
    }

    public void Stop()
    {
        int i = 1;
        foreach (DataColumn c in _table.Columns)
        {
            sheet.Cells[1, i].Value = c.ColumnName;
            sheet.Cells[2, i++].Value = c.Caption;
        }
        book.SaveAs(_logFile);

        AnalogSensor.NewAnalogSensorData
            -= new EventHandler<AnalogSensorDataEventArgs>(AnalogSensor_NewAnalogSensorData);
    }

    void AnalogSensor_NewAnalogSensorData(object sender, AnalogSensorDataEventArgs e)
    {
        if (e.Data.Priority > 0)
        {
            if (_list.InvokeRequired)
                _list.Invoke((MethodInvoker)delegate { UpdateTable(e.Data); });
            else
                UpdateTable(e.Data);

            UpdateChart(e.Data);
        }
    }

    private void MakeTable()
    {
        DataColumn[] keys = new DataColumn[1];

        Type type = Type.GetType("System.UInt64");
        keys[0] = MakeColumn("Index", type, true);
        _table.PrimaryKey = keys;
        type = Type.GetType("System.DateTime");
        MakeColumn("DateTime", type, true);
        _list.Columns["DateTime"].Visible = false;
        type = Type.GetType("System.String");
        MakeColumn("Time", type, false);
        type = Type.GetType("System.Double");
        MakeColumn(SystemNames.PressA, type, false);
        MakeColumn(SystemNames.PressB, type, false);
        MakeColumn(SystemNames.AnalogA, type, false);
        MakeColumn(SystemNames.AnalogB, type, false);
        MakeColumn(SystemNames.AnalogC, type, false);
        MakeColumn(SystemNames.AnalogD, type, false);
        MakeColumn(SystemNames.TempA, type, false);
        MakeColumn(SystemNames.TempB, type, false);
        MakeColumn(SystemNames.TempC, type, false);
    }

    private DataColumn MakeColumn(string name, Type type, bool state)
    {
        DataColumn column = new DataColumn();
        column.ColumnName = name;
        column.DataType = type;
        column.AutoIncrement = false;
        column.Caption = name;
        column.ReadOnly = false;
        column.Unique = false;
        _table.Columns.Add(column);
        _list.Columns[name].AutoSizeMode = DataGridViewAutoSizeColumnMode.AllCells;
        _list.Columns[name].DefaultCellStyle.Alignment = DataGridViewContentAlignment.MiddleCenter;

        return column;
    }

    private void UpdateTable(AnalogSensorData data)
    {
        DataRow row = _table.Rows.Find(_recs);
        if (row == null)
        {
            row = _table.NewRow();
            row["Index"] = _recs;
            row["DateTime"] = data.Time;
            row["Time"] = data.Time.ToLongTimeString();
            row[data.SystemName] = data.Eng;
            _logs = 1;
            _table.Rows.Add(row);
        }
        else
        {
            row[data.SystemName] = data.Eng;
            if (++_logs >= SensorUC.NumberOfActive)
            {
                int i = 1;
                foreach (var item in row.ItemArray)
                {
                    sheet.Cells[(int)_recs + 3, i++].Value = item;
                }
                book.SaveAs(_logFile);
                _recs++;
            }
        }
        if (!_list.Columns[data.SystemName].HeaderText.Equals(data.SensorName))
        {
            _table.Columns[data.SystemName].Caption = data.SensorName;
            _list.Columns[data.SystemName].HeaderText = data.SensorName;
        }
        _list.FirstDisplayedCell = _list.Rows[_list.Rows.Count - 1].Cells[0];
        _list.Update();
    }

    private void UpdateChart(AnalogSensorData data)
    {
        if (data.Line.DataSource == null)
        {
            if (_chart.InvokeRequired)
            {
                _chart.Invoke((MethodInvoker)delegate
                {
                    _chart.Series.Add(data.Line);
                    data.Line.DataSource = _table;
                });
            }
            else
            {
                _chart.Series.Add(data.Line);
                data.Line.DataSource = _table;
            }
        }
        if (_chart.InvokeRequired)
        {
            _chart.Invoke((MethodInvoker)delegate { data.Line.CheckDataSource(); });
        }
        else
        {
            data.Line.CheckDataSource();
        }
    }
}
}