I've been having trouble with the whole Undefined Base Class thing. I can't even say what causes it, because yesterday I had it working without any problems and today it's screwing up yet again. It seems like the issue is that when you import a unit from another mod, it sometimes forget to tack on "_OCimport_2" at the end of it, like this:

class B_US_Operator_DEVGRU_01 : B_Soldier_F_OCimport_02 {

Adding OCimport_02 manually to each of them doesn't work either.

EDIT: I remade it from scratch, checking that it managed to get the OCimport_02 every time I imported a new unit. It worked, but still no idea what causes it.

EDIT 2: It seems the issues start cropping up when you import units from the config. I wanted to tweak some stuff, but when I pack it again, I start getting error messages and invisible units and whatnot.