We had reached our deadline date for registration but we needed to add some classmates that registered late to our attendee list (the registrations are coming in the mail instead of online) We were not able to add them. I changed the deadline date by editing the event, but even though the event shows a deadline almost a week away and an active status, we still cannot register classmates. We have several more to add.

You will need to change the deadline date assigned under Edit Activity, then Save and Publish the page. Then you can add your additional members to the event.