[Solved] Upload file Error: This site can’t be reached in ASP.Net

I want to upload and download audio and videos file in ASP.Net.

I wrote the following code to upload file but unable to upload.

This site can’t be reached when I upload other files it is working fine. 

How to get solution.

    protected void Upload(object sender, EventArgs e)
    {
        string filePath = FileUpload1.PostedFile.FileName;
        string filename = Path.GetFileName(filePath);
        string ext = Path.GetExtension(filename);
        string contenttype = String.Empty;

        //Set the contenttype based on File Extension
        switch (ext)
        {
            case ".doc":
                contenttype = "application/vnd.ms-word";
                break;
            case ".docx":
                contenttype = "application/vnd.ms-word";
                break;
            case ".xls":
                contenttype = "application/vnd.ms-excel";
                break;
            case ".xlsx":
                contenttype = "application/vnd.ms-excel";
                break;
            case ".jpg":
                contenttype = "image/jpg";
                break;
            case ".png":
                contenttype = "image/png";
                break;
            case ".gif":
                contenttype = "image/gif";
                break;
            case ".pdf":
                contenttype = "application/pdf";
                break;
            case ".mp4":
                contenttype = "audio/mpeg";
                break;
            
        }
        if (contenttype != String.Empty)
        {
            Stream fs = FileUpload1.PostedFile.InputStream;
            BinaryReader br = new BinaryReader(fs);
            Byte[] bytes = br.ReadBytes((Int32)fs.Length);

            //insert the file into database
            string strQuery = "insert into tblFiles(Name, ContentType, Data) values (@Name, @ContentType, @Data)";
            SqlCommand cmd = new SqlCommand(strQuery);
            cmd.Parameters.Add("@Name", SqlDbType.VarChar).Value = filename;
            cmd.Parameters.Add("@ContentType", SqlDbType.VarChar).Value = contenttype;
            cmd.Parameters.Add("@Data", SqlDbType.Binary).Value = bytes;
            InsertUpdateData(cmd);
            BindGrid();
            lblMessage.ForeColor = System.Drawing.Color.Green;
            lblMessage.Text = "File Uploaded Successfully";
        }
        else
        {
            lblMessage.ForeColor = System.Drawing.Color.Red;
            lblMessage.Text = "File format not recognised. Upload Image/Word/PDF/Excel formats";
        }
    }