iTunes 12 "Add To Library" simply doesn't work
I'm running iTunes 12 (12.3.2.35, to be exact).
I'm trying to add an AAC file from my desktop to my iTunes library so that I can sync it with my phone. When I go to "Add To Library," select the file, and click "Open", nothing happens. The song isn't loaded into iTunes--not the library, and not the 'now playing' section.
My library is located on an external drive that is mounted, working properly, and that I have read & write permissions on. I have tried restarting my computer.
This is really, really frustrating.