title: Opening Excel File by ClosedXML.dll is showing error "Excel found unreadable content"
body: <p>Hi I have created an excel file using ClosedXML.dll and when I am going to open that file, it showing "Excel found unreadable content" message. My file content has swedish text. I don't know what is the root cause? Is there any way to set language? How to remove that warning please help me. Here is the code snap.</p>
  
  <pre><code>using (XLWorkbook wb = new XLWorkbook())
  {
      wb.Worksheets.Add(dt);  //dt is DataTable
  
      Response.Clear();
      Response.ClearHeaders();
      Response.Buffer = true;
      Response.Charset = "";
      Response.ContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
      Response.AddHeader("content-disposition", "attachment;filename="+fileName+".xlsx");
      Response.ContentEncoding = Encoding.UTF8;
      using (MemoryStream MyMemoryStream = new MemoryStream())
      {
          MyMemoryStream.Capacity = (int)MyMemoryStream.Length;
          wb.SaveAs(MyMemoryStream);
          MyMemoryStream.WriteTo(Response.OutputStream);
          Response.Flush();
          Response.End();
      }
  }
  </code></pre>