Section 25. An executor, administrator, guardian, conservator, trustee, receiver, commissioner or other fiduciary officer appointed by the probate court whose appointment is invalid by reason of an irregularity or of want of jurisdiction or authority in the court which made it, shall account for all money, property or assets coming to his hands in said capacity as if the appointment had been regular and valid; and any bond given in pursuance of such appointment shall be valid and binding on the principals and sureties; and payments to or by a person so appointed, if in other respects properly made, may with the approval of the probate court be ratified and confirmed by the executor, administrator, guardian, conservator or trustee who is afterward legally appointed.