exception from hresult:0x800a01a8 When trying to Export Data from Grid view to Excel

Microsoft.Office.Interop.Excel.ApplicationClass Excelapp = new Microsoft.Office.Interop.Excel.ApplicationClass();
           Excelapp.Application.Workbooks.Add();

           int IndiceColumn = 0;
           foreach (DataGridViewColumn col in table.Columns)
           {

               IndiceColumn++;
               Excelapp.Cells[1, IndiceColumn] = col.Name;
           }

           int IndeceFile = 0;

           foreach (DataGridViewRow r in table.Rows)
           {
               {
                   IndeceFile++;
                   IndiceColumn = 0;
                   foreach (DataGridViewColumn col in table.Columns)
                   {
                       IndiceColumn++;
                       Excelapp.Cells[IndeceFile + 1, IndiceColumn] = r.Cells[col.Name].Value;
                   }
               }
              // Excelapp.Visible = true;
               Excelapp.ActiveWorkbook.SaveCopyAs(saveFileDialog1.FileName.ToString());

               Excelapp.ActiveWorkbook.Saved = true;
               Excelapp.Quit();