MVC2 用RDLC生成报表，为什么提示“本地报表处理期间出错”？

Question

Action 代码如下：        public ActionResult Index()
        {            DBEntityDataContext db = new DBEntityDataContext();            LocalReport localReport = new LocalReport();
            localReport.ReportPath = Server.MapPath("~/Content/Reports/Report2.rdlc");
            ReportDataSource reportDataSource = new ReportDataSource("ExpecetdScore", db.tblExpecetdScore.ToList());
            localReport.DataSources.Add(reportDataSource);
            string reportType = "PDF";
            string mimeType;
            string encoding;
            string fileNameExtension;
            //The DeviceInfo settings should be changed based on the reportType          
            //http://msdn2.microsoft.com/en-us/library/ms155397.aspx         
            string deviceInfo = "<DeviceInfo>" + "  <OutputFormat>PDF</OutputFormat>" + "  <PageWidth>8.5in</PageWidth>" + "  <PageHeight>11in</PageHeight>" + "  <MarginTop>0.5in</MarginTop>" + "  <MarginLeft>1in</MarginLeft>" + "  <MarginRight>1in</MarginRight>" + "  <MarginBottom>0.5in</MarginBottom>" + "</DeviceInfo>";
            Warning[] warnings;
            string[] streams;
            byte[] renderedBytes;
            //Render the report           
            renderedBytes = localReport.Render( //运行到这里会提示“本地报表处理期间出错”
            reportType,
            deviceInfo,
            out mimeType,
            out encoding,
            out fileNameExtension,
            out streams,
            out warnings);
            //Response.AddHeader("content-disposition", "attachment; filename=NorthWindCustomers." + fileNameExtension);           
            return File(renderedBytes, mimeType);        }设置如下：
设置应该没问题吧？
请大家指点啊