I've got version 14.0.2
In Turtorial, I click Get Files in order to download the files that carry the examples to be used in the tutorial. They download okay, but I can Open them (either from InDesign itself or by clicking the Explorer).
I get a dialog box reading:

Adobe InDesign:
"Cannot open the file ".Applycolor.indd". Adobe InDesign may not support the file format, a plug-in that supports the file format may be missing, or the file may be open in another application."