man, do i need help. i had this problem a couple years ago and lived with it but i'm working on a new book project and it's just untenable at this point.
i'm editing pdfs of the previous edition of a book i wrote. the publisher protocol is to add new material by attaching pdfs to the main pdf. of course i use the file attachment tool, and all is well. at first. EVERY TIME i attach a file, i click it to make sure it opens as expected, usually multiple times.
then, inevitably, at some point, the attachments get corrupted, and when anyone – myself, editors, typesetters, whatever – try to open the attachment they get the dreaded error:
Adobe Acrobat DC could not open '1-2 insert 3.pdf' because it is either not a supported file type or because the file has been damaged (for example, it was sent as an email attachment and wasn't correctly decoded).
To create an Adobe PDF document, go to the source application. Then choose Save as Adobe PDF from the PDF dropdown in the Print dialog.
i have no recourse other than to delete and reattach. this happens multiple times with each section and needless to say it KILLS our workflow. i've tried everything: creating the pdfs of the attachments using different methods, different naming conventions. etc etc etc. nothing seems to work.
please please please tell me someone knows what's going on and how to fix it, because two years ago when i dealt with adobe support people they were stumped.
thanks for reading.
ps - my version is acrobat pro DC for mac, version 2015.006.30464, but once the attachments are corrupted, it makes no difference what version the intended reader is using.