PDF portfolios fail on Note Air 2, Neoreader

Hi, looking for help/advice on new Note Air 2. One document failed to load in Neoreader; it appeared as a single page that just said "for best results, get Adobe Reader". Same display for Koreader and PDFview. I eventually found that the original document was a "PDF portfolio". I was able to extract the bulk of the text as a single PDF document and get it to the Note Air 2 via DropBox, where it displayed fine via Neoreader. However, I would like to know a better solution for handling this type of structured document. Is there a different reader I can use? Note that I couldn't find Adobe Reader in the App Store, although there seemed to be many PDF viewers with similar names. Thanks in advance.