The "path variable" that you use for saving the PDF in FIleMaker Pro has to be handled differently than in GO. You'll either need two different scripts or add code that detects the platform and computes a different value for that variable based on whether this is a Go or a Pro user.
On your desktop, you'll find that these PDF's are NOT saved to the documents folder with this code. Instead the Save Records as PDF step will save them to the same folder where the database file is located. You'll either need to change the SetVariable [$FileName ... step to specify the path to the documents folder or modify the Set Variable [$PDFPath ... step to refer to the database file's folder in order to get this to work on your desktop.
Here's one possible solution for a script that only works on your desktop:
Move the Set Variable [$PDFPath step to be just after the Set Variable [$FIleName step.
Modify Save As PDF to refer to $PDFPath instead of $FIleName.