This is 100% the cause. I guess you get "Accessing array index out of bounds on index" either -1 or some large number. You have to check first what the value holds:
pawn Код:
printf("%d", FurnitureData[FurnitureID]);
If it's negative, really big, or your defined invalid value for "FurnitureID", you need to add a surrounding if clause, or change the code in some other way