Would you mind provide the following information for us to do investigation,
#1. What iOS and device you are using?
#2. Does the filename contain accent vowels characters? If so, please refer to this link, Acrobat won't open PDF files if they have accented vowels
Thank you for your patience
it's on iphone 6 with IOS 10.3.1 and no the file name do not contain special character and i can open it on all my other device
Would you mind to let us know what exact the filename is?
there it is,
608108 DD E855 - DETAILS - CONTROLE D'ACCES ET CAMERAS.pdf
and i have like 300 files on my cloud then i use from at least 2 years and the problem just begin from 2 week ago.
It is likely you are encountering the bug discussed in this forum thread:
Our team is working on a fix for the problem, and we will put out a new version with the fix as soon as possible.
-- Mike Laursen
-- Mobile App Development Manager, Adobe Acrobat Reader for iPhone and iPad