Ошибка при заполнение файла excel

Столкнулся с такой ошибкой при заполнение excel:

Вот сам код:

 int i, j;
            var t = membersDataGrid.Columns.Count;
            Excel.Application excel = new Excel.Application();
            excel.Visible = true;
            Workbook workbook = excel.Workbooks.Add(System.Reflection.Missing.Value);
            Worksheet sheet1 = (Worksheet)workbook.Sheets[1];

            for (j = 0; j < t; j++)
            {
                Excel.Range myRange = (Excel.Range)sheet1.Cells[1, j + 1];


                myRange.Value = membersDataGrid.Columns[j].Header;
            }
            for (i = 0; i < t; i++)
            {
                for (j = 0; j < membersDataGrid.Items.Count; j++)
                {
                    TextBlock b = membersDataGrid.Columns[i].GetCellContent(membersDataGrid.Items[j]) as TextBlock;
                    Excel.Range myRange = (Excel.Range)sheet1.Cells[j + 2, i + 1];
                    myRange.Value = b.Text;
                }
            }
            sheet1.Range[sheet1.Cells[1, 1], sheet1.Cells[1, i]].HorizontalAlignment = 3;
            sheet1.Range[sheet1.Cells[1, 1], sheet1.Cells[j + 1, i]].Borders.LineStyle = Excel.XlLineStyle.xlContinuous;

            if (membersDataGrid.Visibility == Visibility.Visible)
            {
                for (int k = 0; k < membersDataGrid.Items.Count; k++)
                {
                    sheet1.Cells[i + j + k + 1, 1] = membersDataGrid.Items[k];
                }
            }
            string name = "";

            sheet1.Range[sheet1.Cells[1, 1], sheet1.Cells[1, t]].Insert();
            sheet1.Range[sheet1.Cells[1, 1], sheet1.Cells[1, 1]].Value2 = name;
            sheet1.Range[sheet1.Cells[1, 1], sheet1.Cells[1, t]].Borders.LineStyle = false;
            sheet1.Columns.EntireColumn.AutoFit();
            sheet1.Range[sheet1.Cells[1, 1], sheet1.Cells[1, t]].Merge();
            sheet1.Range[sheet1.Cells[1, 1], sheet1.Cells[1, t]].HorizontalAlignment = XlHAlign.xlHAlignCenter;
        }

А вот что в таблице:

Может кто подсказать в чем проблема?