66. Validation of acts and proceedings.

(a) the existence of any vacancy in, or any defect in the constitution of the State Urban and Country Planning Board or any Local Planning Authority;
(b) any person having ceased to be a member;
(c) any person associated with the State Urban and Country Planning Board or any Local Planning Authority under section 13 having voted in contravention of the said section; or
(d) the failure to serve a notice on any person, where no substantial injustice has resulted from such failure; or
(e) any omission, defect or irregularity not affecting the merits of the case.