La. R.S. 33:3689.17

If the validity of any paving certificates issued under the provisions of R.S. 33:3689.1-33:3689.17 is not raised within thirty days from the date of publication of the resolution or ordinance issuing said paving certificates, the authority to issue said paving certificates, the legality thereof and of the local or special assessments necessary to pay the same shall be conclusively presumed and no court shall thereafter have authority to inquire into such matters.