external container pdf opening as png

Version 2

    I have my .pdf's stored externally on FMPS13 on a PC. When I try to open the .pdf it will say "The file "XXXXXXXXX.png" could not be opened" "It may be damaged or use a file format that Preview doesn't recognize"


    The file is a .pdf and it opens if I store it internally. All other formats seem to open, .doc, .xlx, etc. and not all the .pdf display this behavior.


    I am using a script to open and opening from a Mac using FMP13.


    Anyone have any suggestions on what is going on?