ASP.NET ReportViewer Native compiler return value: ‘[BC2001] file’ error

Recently restored one of our servers and I encountered this error while trying to view a report:

An unexpected error occurred while compiling expressions. Native compiler return value: ‘[BC2001] file …. 


1. Solving this seems so easy, first check the identity of the AppPool where the website is running:

2. From the command prompt type: %windir% and look for the temp folder. Add read/write permission to temp folder of windows to user in step 1.

Note: In other cases  the temp folder is located somewhere else, so to check where it’s located go to System Properties -> Advance -> Environment Variables. In the System Variables look  for the TEMP or TMP:





Asp.NET – ReportViewer Control not working on IIS7

We recently upgrade our webserver from II6.0 to IIS 7.5, everything works fine except the ReportingViewer control that renders the MSSQL Reporting in Asp.NET. It shows a blank page with missing icons in IE 6.0 and displays missing resource on FireFox.

To solve the problem, you need to add a new Manager Handler in IIS Manager.

Steps are as follows:

1. Open IIS -> Go to Sites – > {Your WebSite} -> In the IIS section double click Handler Mappings

Handler Mappings in IIS7

2.  On the Action (Right side) click Add Managed Handler and set the ff. properties to:

Request Path: Reserved.ReportViewerWebControl.axd

Type: Microsoft.Reporting.WebForms.HttpHandler

Name: ReportViewerWebControl

Click Ok.

Should be fixed now.




Storing files to mssql database and downloading using Asp.NET

1) First create a new column and set it as varbinary(MAX) for the datatype.

2) Use this code to store the file to database:

            //Read File to Bytes
                    FileStream st = new FileStream(<Location of the file>, FileMode.Open);
                    byte[] fileData= new byte[st.Length];
                    st.Read(fileData, 0, (int)st.Length);

                    SqlParameter[] param = new SqlParameter[] { new SqlParameter(“@ID”,<Reference ID>),
                                                    new SqlParameter(“@Data”,fileData)  };

            int i = SqlAccessor.ExecuteNonQuery(<ConnectionString>, SqlAccessor.SqlCommandBuilder(new SqlCommand (<Stored Procedure Name>), param), CommandType.StoredProcedure, out retVal);

 I’ve used Application Blocks to simplify data operation.

To Retrieve the data and to be downloaded from an ASP.NET Page:

3)  I created a function that returns a byte array with ID as parameter

 public static byte[] GetFileFromDB(string id)
        object[] retVal = null;
        byte[] file = null;
        SqlParameter[] param = new SqlParameter[]
            new SqlParameter (“@id”, id)
        string _connString = ConfigurationManager.ConnectionStrings[<ConnectionStringName>].ConnectionString.ToString();
        SqlDataReader reader = SqlAccessor.ExecuteReader(_connString, SqlAccessor.SqlCommandBuilder(new SqlCommand(“SourceFileLogSelFileDataProc”), param), CommandType.StoredProcedure, out retVal);

        if (reader.Read())
            file = (byte[])reader[“<varbinary column that we define in Step 1>“];

        return file;

4) And on the ASP.NET Page itself, on the Page_Load event:

           byte[] fileData = Utils.GetFileFromDB(<ID>);
            Response.AddHeader(“Content-Disposition”, “attachment; filename=” + <filename>);
            BinaryWriter bw = new BinaryWriter(Response.OutputStream);
            Response.ContentType = ReturnExtension(<file extension>);

 5) I have another method to determine the ContentType:

  private string ReturnExtension(string fileExtension)
        switch (fileExtension)
            case “.htm”:
            case “.html”:
            case “.log”:
                return “text/HTML”;
            case “.txt”:
                return “text/plain”;
            case “.doc”:
                return “application/ms-word”;
            case “.tiff”:
            case “.tif”:
                return “image/tiff”;
            case “.asf”:
                return “video/x-ms-asf”;
            case “.avi”:
                return “video/avi”;
            case “.zip”:
                return “application/zip”;
            case “.xls”:
            case “.csv”:
                return “application/”;
            case “.gif”:
                return “image/gif”;
            case “.jpg”:
            case “jpeg”:
                return “image/jpeg”;
            case “.bmp”:
                return “image/bmp”;
            case “.wav”:
                return “audio/wav”;
            case “.mp3”:
                return “audio/mpeg3”;
            case “.mpg”:
            case “mpeg”:
                return “video/mpeg”;
            case “.rtf”:
                return “application/rtf”;
            case “.asp”:
                return “text/asp”;
            case “.pdf”:
                return “application/pdf”;
            case “.fdf”:
                return “application/vnd.fdf”;
            case “.ppt”:
                return “application/mspowerpoint”;
            case “.dwg”:
                return “image/vnd.dwg”;
            case “.msg”:
                return “application/msoutlook”;
            case “.xml”:
            case “.sdxl”:
                return “application/xml”;
            case “.xdp”:
                return “application/vnd.adobe.xdp+xml”;
                return “application/octet-stream”;

Hope this helps.