I've been using FMP 14 on the mac since it was released and create PDFs all the time. You might want to check in with FM support.
HOPE THIS HELPS.
Make a print screen for show the error of the corrupt pdf.
I contacted technical support, they figure its a scripting problem.
I can write pdfs from "save as" in one database, but not in another.
When I attempt to use a script to "save as a pdf", that worked before in version 12 it saves it as a corrupt file.
Make a copy of your layout to use for testing this issue. Try the following, one change at a time producing a PDF after each change to see if it has the same problem:
Change the theme
Change all text to a different "plain vanilla font"
Remove one layout object from the layout at a time.