§ 163. Assessment not invalidated by irregularities. No assessment or
tax shall be vacated, set aside, canceled, annulled, reviewed or
otherwise questioned or affected by reason of any error, omission,
irregularity or defect, not actually fraudulent, in any of the steps or
proceedings required to be had or taken as preliminary to, or in the
making of, the assessment, or in the levying or collection of the tax,
nor in relation to or in connection with any proposal, designation of
materials, contract, work or improvement for or on account of which such
assessment was made or tax imposed. But all property shall be liable to
assessment and all assessments shall be valid and of full force and
effect notwithstanding any such error, omission, irregularity or defect.