QUESTION AND ANSWER
Why are attendees getting "An error occurred. Please try again later" message when joining webinar
If the Organizer had required a password for the webinar and then edited it to not require password after starting the webinar any attendee joining after the change will get the message "An error occurred. Please try again later" and be unable to join the session.
Attendees who join via the mobile app will be able to join if they have the webinar password.