Section 24. If the authority or validity of an act or proceeding of the probate court or of a person acting as executor, administrator, guardian, conservator, receiver, commissioner or other fiduciary officer appointed by the probate court, or trustee is drawn in question by reason of an alleged irregularity, defective notice or want of authority, any party interested in or affected by such act or proceeding may apply to the probate court having jurisdiction of the subject matter relative to which the act or proceeding has been had, and the court, after notice to all parties interested, and to the persons who may be the parents of such parties not in being, with power to appoint a guardian or next friend to represent the interests of any person unborn or unascertained, may hear and determine the matter and confirm the act or proceeding, in whole or in part, and may authorize and empower the executor, administrator, guardian, conservator, receiver, commissioner or other fiduciary officer appointed by the probate court, or trustee, or any successor or other person who may be legally appointed to act in the same capacity, to ratify and confirm such act or proceeding and to execute and deliver such deeds, releases, conveyances and other instruments as may be found necessary therefor; but no act or proceeding shall be ratified or confirmed which the court might not have passed or authorized in the first instance upon due proceedings.