Asp.net mvc 读/写.xlsm文件mvc.net

嗨，我尝试使用Excel文件和C#。当我尝试写入和上载时，文件被损坏，我无法打开上载的文件。如果你能帮忙，谢谢

XLWorkbook wb = new XLWorkbook(Server.MapPath("~/Areas/Credit/App/Files/Book1.xlsm")) { Author = "AAICCo" };
            var ws = wb.Worksheet("Main");
            var model = _caseBusiness.GetRatingExcelReport(caseRateDateId);
            int count = 9;
            foreach (var item in model)
            {
                wb.Worksheet("Main").Cell(count, 1).Value = item.BaseTitle;
                wb.Worksheet("Main").Cell(count, 2).Value = item.TypeTitle;
                wb.Worksheet("Main").Cell(count, 3).Value = item.Title;
                wb.Worksheet("Main").Cell(count, 4).Value = item.Code;
                wb.Worksheet("Main").Cell(count, 5).Value = item.Id;
                wb.Worksheet("Main").Cell(count, 6).Value = item.CaseRateDateId;
                wb.Worksheet("Main").Cell(count, 7).Value = item.RawValueDecimal != null ? item.RawValueDecimal.ToString() : item.RawValueInput;
                wb.Worksheet("Main").Cell(count, 8).Value = item.Result;
                wb.Worksheet("Main").Cell(count, 9).Value = item.MaxScore;
                wb.Worksheet("Main").Cell(count, 10).Value = item.TrendIndex;
                wb.Worksheet("Main").Cell(count, 11).Value = item.SUMMultiplierQuestion;
                wb.Worksheet("Main").Cell(count, 12).Value = item.Weight;
                wb.Worksheet("Main").Cell(count, 13).Value = item.ThresholdScore;
                count++;
            }
            //var table = wb.Worksheets.Worksheet("Main").Tables.ToList();
            var base64Data = "";
            using (MemoryStream stream = new MemoryStream())
            {
                wb.SaveAs(stream);
                base64Data = Convert.ToBase64String(stream.ToArray());
            }
            wb.Dispose();
            //return wb.Deliver("NewRating_ExcelReport" + DateTimeUtility.ToClientDateByCulture(DateTime.Now) + ".xlsm");

            return jsonModel(base64Data);