Check if you have all the default scripts in the secnarios folder. They are text files and there should be
Basicnpc.txt
door.txt
guard.txt
specobj.txt
trap.txt
plus one which will be your scenario file name.txt
If they aren't there then I can say that the error is coming from the lack of the scripts.
You can find copys of them all in the BOA file folder if their missing