Title says it all.
As far as I can tell, if a script tries to manipulate FFC0 (there isn't one, they start numbering at 1) the game crashes at runtime.
Script Manipulates FFC 0 = Crash
Same happens if you assign a ffc to use CSet 6.5 or accidentally mix up a random scripts D[] vars, or the moon is full and you sneeze.
Now now, DarkDragon's compiler is more robust than THAT.
I've added some bounds checking to some variables, but robust error-checking of all variables will have to wait for a complete code redesign.