Insert File (pdf) from afp share returns error 100

[vinnygi]

I'm trying to use a script to Insert File from a specific AFP share into a container field.  Every time I try, I get a 100 error (File is missing) from Filemaker.  If i change the path to a local file, it works fine.

I've tried hard-coding the path; using a variable; using a global field as a reference. 

I've also tried all the permutations of the path according to filemaker's requirements...

filemac:/<path to file>, file:/<path to file>, using /Volumes, /ip address of the share, etc.  For example: "filemac:/Volumes/Folder one/Folder two/filename.pdf", etc.

No matter what I try, I get the 100 error.