No error is generated during trading when the specified amount of a goods type isn’t bought. This shortfall can happen because of lack of money or lack of the goods.
Example: When no error appears you assume that there was no problem, and the trade went through alright, when in fact nothing may have been bought... Say some Louisdore are transferred into a ship or baggage train in the same month that it is to buy the goods, and because the national warehouse is out of money, no money is transferred. Then the ship or baggage train ‘completes’ its trading, and buys nothing because it has no money. So it appears that money has been transferred, no goods bought, and yet the money has disappeared. Confusing, eh?!