You can still have a valid meeting even if there was a mistake in how it was called. If all members who can attend and vote are at the meeting and do not complain about the mistake, or if they all agree to ignore it, the mistake is waived. You can also have a valid meeting if a member did not get notice of it by accident, as long as it does not go against the society's rules. If a member was supposed to get notice of a meeting but did not, this does not automatically make the meeting invalid. However, the society's rules can override this. The society's rules are outlined in its constitution. You can find more information about this in the Schedule 1 cl 2(3), (3A) for comparison.