Sorry about the very delayed response, and the rather needless post, but I felt this was necessary for those of you that get the joke.
Actually, I just thought of another fix for why this trick might not work in edited projects. It's possible that one fix may be starting a new save file. That's fixed certain types of bugs in my own project before.
Anyways, I suppose what you mentioned might be possible, but I don't know if it's really a bug. It's almost like Essentials looks for places to throw wrenches into, hoping to make your game developing experience a little harder. Also, it should work in edited kits, but other edits to the editor scripts may interfere. Or maybe Essentials isn't in the mood to cooperate on that day. Who knows. Really though, it's probably because of the compiler. Compiling the game should fix it, but then again it may not be designed to be flexible enough for various mods.