To check, if the person appears near the bottom of the save file where it lists the name, sex, race, id, etc. does that mean that they're in the globals.slaves area?
Edit: If not then I have no idea where to look. About the only bit of coding I've messed with was some C++ in highschool, editing saves on this, and messing with some config files for other games.
Edit 2: Changed a Halfkin Bunny's race (genealogy with orc 37) to Orc and race_display left on Halfkin Bunny, same exact errors.