ASP.NET

try
       {
           stmtDataSetTableAdapters.IOB_StmtTableAdapter ds = new stmtDataSetTableAdapters.IOB_StmtTableAdapter();
           // Create Report DataSource
           ReportDataSource rds = new ReportDataSource("IOB_Stmt");

           // Variables
           Warning[] warnings;
           string[] streamIds;
           string mimeType = string.Empty;
           string encoding = string.Empty;
           string extension = string.Empty;

           // Setup the report viewer object and get the array of bytes
           ReportViewer viewer = new ReportViewer();
           viewer.ProcessingMode = ProcessingMode.Remote;
           viewer.LocalReport.ReportPath = "~/Report.rdlc";
           viewer.LocalReport.DataSources.Add(rds); // Add datasource here

           byte[] bytes = viewer.LocalReport.Render("PDF", null, out mimeType, out encoding, out extension, out streamIds, out warnings);//Error Occured

           // Now that you have all the bytes representing the PDF report, buffer it and send it to the client.
           Response.Buffer = true;
           Response.Clear();
           Response.ContentType = mimeType;
           Response.AddHeader("content-disposition", "attachment; filename=" + fileName + "." + extension);
           Response.BinaryWrite(bytes); // create the file
           Response.Flush(); // send it to the client to download
       }
       catch (Exception ex)
       {
           Response.Write(ex.ToString());
       }