If someone is not visible, confirm you opened the correct Event and search by name or email. RSVP check-in shows only confirmed registrations; a waiting-list party must be promoted before attendance. Search first before adding a walk-in.
If a button is closed, check timing. RSVP check-in opens automatically 30 minutes before the Event starts and runs until Event end. On the Event date, an authorized event user may open it earlier. A Volunteer assignment accepts a new check-in until its shift ends. Cancelled Events, cancelled shifts, and ended participation block new check-in.
If a walk-in cannot be added, confirm the Event is published, registration is still open, the whole RSVP party fits, no active waiting list blocks bypass, and the selected Volunteer shift has space. Event Staff cannot add Volunteer walk-ins. Contact Support if the visible explanation does not resolve it.