Rhode Island General Laws Title 33. Probate Practice and Procedure § 33-19-21. Irregularities in proceedings

(1) That the decree was granted by a court of competent jurisdiction;

(2) That the person authorized to make the sale gave a bond, if bond was required, which was approved by the probate court;

(3) That the notice of the time and place of sale, if at public auction, was given according to law and the order of the court; and

(4) That the premises were sold by public auction in accordance with the notice, or by private contract in pursuance of the decree, and are held by one who purchased them in good faith or by some one claiming under him or her.