“They are not free to marry another person in the Church unless they get their first marriage annulled.”
But if the Church didn’t consider the first marriage valid, then why would an in-valid marriage need to be annulled if it didn’t exist in the first place?
That’s not logical...
You think it’s illogical because you don’t understand what an annulment is. An annulment, whether civil or ecclesiastical is a declaration that the marriage did not exist. In Kansas in a civil context, the court has to rule that a marriage was void because of such things as a material mistake making the vows void or that it is void ab initio because of lack of capacity. An example of the first would be that the woman lied about having had children previously and that was important to the man and he would never have married her had he known. An example of the ab initio grounds is if one of the parties is mentally incompetent or already married. In all those cases, the parties have a piece of paper saying that they’re married and they need a piece of paper saying that they are not.