Inconsistent crashes are a nightmare to track down sometimes!
Just to give you some more stuff to think about - here is an example when NULL is specifically sent to die().
In ACMD(do_quit)
line 52 (in stock code) we see:
Code:
else if (GET_POS(ch) < POS_STUNNED) {
send_to_char(ch, "You die before your time...\r\n");
die(ch, NULL);
} else {
So if a player is incapacitated and they type quit - NULL gets sent as the killer. That might explain why in the third screenshot we see argument = "quit", then the reference to the faulting function die().
That is why when we expand on code functions it is important to look for all the places the function gets used. Adding "dummy checks" is never a bad idea too, you'll often see them at the start of functions like checking that *ch isn't an NPC or that *arg isn't empty etc..
