Preflight keeps saying "Unable to save the PDF File after post processing"

Question

I'm at a loss how to overcome this. Spent almost a whole day, together with another person, trying to fix it with no success!
I use Adobe pro CC on a PC
I usually receive pdf files from this one client who edits and formats a book in Mac Pages. Up until a few days ago I had no problems converting the client's pdfs into pdf/x3, but the last three versions of the latest file have stumped me.
Just to test, I first just tried to convert the file (33MB), unchanged, to pdf/x3 using the save as other option - message reads  "the document has been saved, however, it could not be converted according to the selected standard profile: convert to PDF/X. Please use preflight with the profile "Convert to PDF/X" in order to identify those properties of the document which prevent it from being compliant to this profile"
if I then choose under Profiles - convert to PDF/X3 - it says no problems found, and appears to have saved the file. If I try to save again as a pdf/x3, just to make sure, it then tells me it's not pdf/x3 compliant
OK - so then I go back to preflight - and choose the standards function - then pdf/x3, then continue with the default colour profile. About halfway through the conversion, at the point of saving the file,  I get the message "unable to save the pdf file after post processing"
So far I've had no luck figuring out what this is.
I then choose the option of "verify compliance of ppdf/x3" - message reads "pdf/x3 version key (GTS_PDFXVersion) missing", and "Trapped key not true or false"
Help!! How can I be sure the file converted / or not?
kim

Answer 1

Yes I was/am aware of Preflight's inability to play nicely over cloud technologies in certain cases, especially wrt Standards technologies, this will be partially addressed in an upcoming version of Preflight without saying too much.  But the same thing could theoretically have happened if the file was also located on another local network client or server.  Leaving aside the argument that this may violate the Acrobat User Agreement - since purchasing the software, the user agrees to employ its functionality on a single host system and precludes host-client-based scenarios - this simply is not a supported use, meaning the user may not have expectations that it will work at all, if the applications requirements are not observed.  There do exist server-solutions for Preflight files within networks, but Acrobat and by extension Acrobat Preflight is not one of those solutions, and (still) belongs in the single host-based desktop environment.
However most (99.9%) functions within Acrobat <-> acrobat.com file exchange are supported, file syncing across multiple devices will soon be supported, but Standards compliance is still admittedly a problem at this point.  Some testing has been done using 3rd party cloud technologies starting with enterprise-based solutions, such as Office 365, and this will continue to ramp up to include other 3rd party products.
As for the second point, Preflight will usually change the PDF version to be complaint, are you saying that it was unable to do so in this case?  It seems that this error should have popped up during the normal Preflight conversion attempt.  Personally I think solving a workflow problem using the print path is a little bit of a heavy-handed approach, but if helped and the results are acceptable, then that is good.  Since that path is non-existent on a Mac, as one needs to Save as Adobe PDF from the Print dialog's PDF drop-down menu, I am assuming your workflow involved file creation on a Mac, then further processing on Windows using the PDF printer.  I am wondering if a simple resave/Save As... to PDF with overwrite on a Mac, or Preflighting the file using a PDF version compatibility profile before the PDF/X conversion would have helped.  Since there are such a multitude of methods that a PDF can be created, there are also many ways within Acrobat that a user can shape the file to be compatible with the expected workflow, ie, 'many ways to skin a cat', without being morbid.