Hello Aspose Team,
Thanks for your posting and using Aspose.Cells.
Excel to PDF conversion depends on the number of pages. If there are lot of pages like say 500-5000 or more, it will take time accordingly. Aspose.Cells converts the Excel file into PDF as per Microsoft Excel Print Preview.
So open your excel file in Microsoft Excel 2010 or later and check the Print Preview and see how many pages are there.
For your help, I have attached the sample excel file which has total of 5 pages. You need to select Print Entire Workbook and No scaling to get correct number of pages. Please check the screenshot attached by me for your reference.
Please also download and try the latest version: and see if makes any difference and resolves your issue.
I have also made this thread Private, so now only you or Aspose Staff members can access your files in this thread. So it is now safe for you to attach the files and provide to us for our investigation.