I have used Files on my PC and iPhone since Sep 2008 without any problems but today I copied a 4 page, 591KB pdf that I created on my pc, to my iPhone and though Files opens that pdf and displays the file name and "1 of 4" in the header, none of the pages display - there is nothing but blank area on each page - I can see the page breaks but no content.
I tried emailing the pdf from Files to my email address and that works perfectly and I can open the email as well as the attached pdf on my pc's email client. I have also tried to extract 1 page from the 4 page "problem" pdf to see if that makes a difference but the results are the same: just a single blank page pdf.
If it makes any difference, I did recently upgrade from Acrobat 9 to version X but I have created additional pdfs using Acrobat X and they have all, thus far, displayed correctly in Files.
It is not the end of the world if I can't view this specific file but it makes me wonder if there is some consistent problem that will cause me not to have Files read a critical pdf that I may need to access in the future.
Thanks for your assistance.