Louisiana Revised Statutes Tit. 33, § 2843. Plea of estoppel

The plea of estoppel shall never be allowed in matters of local or municipal assessments where there are radical defects in the proceedings leading up to the local assessments, but the plea shall have full effect as against mere subsequent irregularities or informalities therein where no protest has been made thereto. This Section shall not apply to the levying of taxes for the security of any issuance of bonds.