Just downloaded the update and tried to output a document to PDF format.
If the FM file is located in the root directory (not under any "folder"), PDF output fails. The version 15 just created a folder (directory) with the same name of the document, and save a PDF file there.
I have Adobe Acrobat Professional and it outputs to a PDF file with no problem if I "print" (to Adobe Acrobat).
The work around is to save the FM file under a folder, and output a PDF file from there.