Upon such appeal the Supervisors may remedy and correct any error or informality in the proceedings and revise and correct any of the acts or determinations of said Director relative to said work; may confirm, amend, set aside, alter, modify or correct the assessment in such a manner as to them shall seem just, and may require the work to be completed according to their directions, and may instruct and direct said Director to correct the warrant, assessment or diagram in any particular, or to make and issue a new warrant, assessment and diagram to conform to their decisions in relation thereto, at their option.
All the decisions and determinations of the Supervisors, upon notice and hearing as in this Article provided for, shall be final and conclusive upon all persons as to all errors, informalities and irregularities whether they do or do not appear upon the face of the warrant, assessment or diagram.
No assessment, warrant or diagram, after the issuance of the same, and no proceedings prior thereto, shall be held invalid by any court, or otherwise, for any error, informality, or other defect in the same, when notice of the recordation in the office of the Department of Public Works of the assessment, diagram and warrant, and of hearing with regard thereto, has been actually published as provided in Sections 217 to 220, inclusive, of this Article.