That looks odd...
This was curious. Clearly whatever this ‘???’ was, my app couldn’t interpret.
The app was presently running on the Railo/Nginx/Ubuntu stack, so out of curiosity and good practice, I switched over to the ACF/Windows stack to see what I’d find. I found this:
Turns out that this symbol combination (ï»¿) is the infamous BOM (Byte Order Mark). Some Googling revealed its purpose and place in the computer science world. It also exposed that the BOM can create problems in a variety of environments. The solution was simple: all I had to do was open the file in a good text editor and re-encode the file with it, removing the BOM. This is not possible in all text editors, but most modern versions have an encoding feature in them.
Removing the BOM
I use Sublime 2, so this is the process that I used:
Opened the file that the BOM preceded (the file that followed the BOM in the JSMin compression)
Went to the File menu option in the top left of Sublime Text Editor
Put my mouse cursor over the ‘Save with Endoding’ option
Selected ‘UTF-8’. This removed the BOM from the file
Below The Surface
One of the things I questioned in this process was the purpose of the BOM, aside from causing me this particular pain. There are a variety of articles available on the topic, including the Wikipedia page I noted earlier and this one.