Why Won't InDesign Sample Scripts work in InDesign 2019?

I encountered a strange issue recently. I was creating a business card imposition in InDesign. I opened the Scripts panel, and then ran CropMarks.applescript. Nothing happened.

My compute seemingly locked up for a moment, but no crop marks appeared. After a  minute or so of investigation, I realized that InDesign 2018 had launched. But I was using InDesign 2019...

I went back to InDesign 2018, and it displayed the following dialog box:

It turns out that when InDesign 2019 was shipped, no one at Adobe had changed the hard-coded application version in the sample Applescripts. 

The workaround is that you simply need to change them to be "2019" instead of "2018." Alternatively, you can use the corresponding sample javascripts in the Samples folder for the job.