Function call error (binary)

[Niemand]

This message is rare, and I have never seen any explanation for why it will be displayed. I've managed, however, to track down one possible cause: calling char_attitude_to_char with both arguments being the same character, or one being a nonexistant character. I don't know what, if any other triggers may be out there, but considering how much trouble this one gave me, I thought I'd write it down where other people could find it.

[Lazarus.]

I believe I've seen this one before, possibly for calling nonexistant creatures. Or maybe I'm confusing it with unary-- which I've certainly seen plenty of (and still can't remember what for.)