What does "the webinar is full" mean?
If you are trying to join a session but received a message stating "The webinar is full", then the session already has the maximum number of attendees that are allowed. You will not be able to join the session unless one of the attendees who has already joined leaves the session.
This is because each GoToWebinar organizer's account has a subscription plan with a maximum number of attendees that they can have per session. Once that maximum is reached, no more attendees can join.
Note that although organizers can register more attendees than their capacity allows, only the first 100, 500 or 1,000 attendees to join will be allowed into the session (depending on the plan selected by the organizer). This means that even if you received a Registration Confirmation message, you will not be able to join if the capacity has been reached.
To ask if the session is being recorded or if another session will be scheduled, please contact the organizer (i.e., the person who invited you to the session).