Here's the issue I couldn't get resolved, and today I see that the official solution also does not resolve it:
The picture instructions show that if the user inputs a nonexistent id number, an error message should appear saying that there's no such number. Both mine and the official solution had that message worked into the interface.
The problem is that with the PDF render, there is always an output, so the "No Output Files Message" is never triggered. Even if the user inputs a nonexistent id number (400 was the one I used for testing), the workflow outputs a blank PDF and no error message.
I looked through 3-4 pages of solutions and didn't see anything that would solve this problem. I tried to work something out with an error message that would stop the workflow before the blank PDF was generated, but couldn't figure it out.
Any ideas, Alteryx Nation?