Hi Fang,
Thanks for your posting and using Aspose.Cells.
Please download and try the latest version: Aspose.Cells
for .NET v8.3.1.1 it should fix your issue.
I have tested this issue with the following sample code and it generated the pdf file successfully. I have attached the output pdf for your reference.
C#
string filePath = @“F:\Shak-Data-RW\Downloads\Report08040010_ec8ce169-6705-46e9-a071-2ac39a251ad8.xls”;
Workbook workbook = new Workbook(filePath);
workbook.CalculateFormula();
workbook.Save(“output.pdf”);