This article provides additional information on how the PDF Import script works and how to correct common issues.
How the PDF Import Script Works
The mag+ PDF Import Script included with the mag+ InDesign Plugin requires well-formed PDFs. It specifically relies on the /Count, xref, startxref, and /Root tags. Without these tags, the script cannot properly determine the number of pages to import.
You can confirm that the PDF is malformed by opening it in a text editor and searching for the text "/Count." If it does not appear, then the PDF will not import properly.
Note: Version 5.2.1 and earlier of the Mag+ InDesign Plugin included a PDF Import Script that displayed an incorrect page count when it reported errors parsing the PDF. A new script is attached to this article which will properly display the malformed page count, helping reduce confusion. To install, simply drop the new script into the Adobe InDesign > Plug-Ins > Mag+ folder.
How to Fix Badly Formed PDFs (OS X)
The following steps use Apple Preview to allow an OS X user to fix a badly formed PDF. Unfortunately, Adobe Acrobat does not correct the issue at this time.
1. Open the PDF in Apple's Preview application.
2. Go to File > Save As... and save a copy of the PDF.
Preview will add the missing tags.