I receive the exception:
Thanks for your posting and using Aspose.Cells.
Please download and use the latest version: Aspose.Cells for .NET (Latest Version) it works fine.
We have converted your file into pdf with the latest version using the following code and it did not throw any exception. I have attached the output pdf for your reference.
string filePath = @“F:\Shak-Data-RW\Downloads\convert_pdf.XLSX”;
Workbook workbook = new Workbook(filePath);
workbook.Save(filePath + “.out.pdf”);