why would you need Reader 8? PDFs can be opened in any of the later Reader versions. Unless you are attempting to open it in the browser - that is not supported any more as the browser companies have decided to kick out the plugin technology needed to open Reader in Chromw, Edge or Mozilla. You can still open those PDF directly in the Reader for testing.
The PDF I sent you was created with AEM Forms Deisgner (which is a newer LiveCycle Designer). YOu can view its functionality in any Adobe Reader by downloading from my URL and open the file. If you want to edit it you can open my PDF directly in the Designer. If your designer is very old you might get a warning - but you should still be able to open and look at it.