Illustrator CC ExternalObject load failing but works in CS5

I have a script that loads an external library as follows:

if(typeof PCDesEO == 'undefined' ) {

    var libFilename = "/Library/Frameworks/PCDesEO.framework";

    PCDesEO = new ExternalObject("lib:" + libFilename);

};

It works fine in CS5, but when I upgraded to CC, the "new ExternalObject" line fails with an I/O Error (error 52).

Any thoughts?

Thanks,

Anurag.