Section 15. Validation of official acts performed before filing official oath or undertaking

If a public officer, duly  chosen,  has  heretofore
  entered,  or  shall  hereafter enter on the performance of the duties of
  his or her office,  without  taking  or  filing  an  official  oath,  or
  executing  or  filing  an  official  undertaking,  as  required  by  the
  constitution, section ten of this article, section  twenty-five  of  the
  town  law  or section one hundred four of the uniform justice court act,
  or by any general or special law, his or her acts as  such  officer,  so
  performed,  shall be as valid and of as full force and effect as if such
  oath had been duly taken and filed, and as if such undertaking had  been
  duly  executed  and filed, notwithstanding the provisions of any general
  or special law declaring any such office vacant, or authorizing it to be
  declared vacant, or to be filled as in case of vacancy, or imposing  any
  other  forfeiture or penalty for omission to take or file any such oath,
  or to execute or file any such undertaking; but this section  shall  not
  otherwise  affect any provision of any general or special law, declaring
  any such office vacant, or authorizing it to be declared vacant,  or  to
  be  filled  as  in  case of vacancy, or imposing any other forfeiture or
  penalty, by reason of the failure to take or file any such  oath  or  to
  execute or file any such undertaking; and this section shall not relieve
  any  such  officer from criminal liability for entering on the discharge
  of his or her official duties without taking  or  filing  such  oath  or
  executing or filing such undertaking in accordance with such provisions.