No act or proceeding of the Bureau or the Governing Council or any Committee shall be invalid merely by reason of-
(a) any vacancy in, or any defect in the constitution of, the Bureau or the Governing Council or the Committee; or
(b) any defect in the appointment of a person acting as a Director-General or Secretary of the Bureau or a member of the Governing Council or the Committee; or
(c) any irregularity in the procedure of the Bureau or of the Governing Council or the Committee not affecting the merits of the case.