I am trying to use Spire dll to convert an excel file to jpg.
The  xlsm file:

I use this code to convert it to jpg :
    Workbook workbook = new Workbook();
    workbook.LoadFromFile(@"D:\a.xlsm");
    Worksheet sheet = workbook.Worksheets[1];
    sheet.SaveToImage("exceltoimage.jpg");
    System.Diagnostics.Process.Start("exceltoimage.jpg");
But the output is like this some of the cells can't be converted why do I mean (#name)?

I have this warning on my page :
