Validation of acts and proceedings. - No act done or proceedings taken under this Act shall be

No act done or proceedings taken under this Act shall be questioned merely on the ground of - (a) the existence of any vacancy in or any defect in the constitution of the Authority; (b) any person associated under Section 24 having voted in contravention of the provisions of this Act in this behalf; (c) the failure to serve a notice on any person where no substantial injustice has resulted from such failure; (d) any omission, defect or irregularity not affecting the merits of the case.