erreur sur l'existence de l'objet

OBS: Both parties may be mistaken as to the existence of the subject-matter. Thus in Galloway v. Galloway a separation deed between a man and a woman, who mistakenly thought that they were married to each other was held void, because it purported to deal with a marriage which did not exist. Similarly the purchase of an annuity is void if at the time of the contract the annuitant has died, so that the annuity no longer exists.