1776. Where the prescribed formalities have not been observed, the sale of an enterprise may not be set up against creditors of the seller who have claims prior to the date of conclusion of the sale, unless the buyer pays them, up to the value of the property he has bought.
The fact that the sale may not be set up may only be invoked, on pain of forfeiture, within one year from the day on which the creditor becomes aware of the sale and, in any case, within three years from the act of sale.