Problems creating object

I was trying to create a custom object according to this Eternity Wiki article, and I keep getting the error "E_ProcessSprites: no sprite names defined." I figured it was due to my incompetency, so I copied the example work into the EDFROOT file and it still gave me the same error. Is this wiki article out of date now?

I should note I'm using the current stable release, 3.40.30.

EDIT: Looks like commenting out all the code in EDFROOT gives me the same problem, so I'm starting to think it could be something else entirely that I'm doing wrong

You need to do

stdinclude("root.edf")

in your own EDF file, and then define your custom definitions. Use that file as your root EDF by dragging it onto EE or using the -edf parameter, or insert it as EDFROOT into a wad/pke file. Make sure EDFROOT is in the global namespace of the wad or pke.