🔍 Understanding the Issue
This error typically occurs when your event is set to RSVP Registration, which requires guests to be pre-listed in your Attendee List. If a guest's email isn't on this list, they won't be able to register.
✅ Solutions
Option 1: Add Guests to Your Attendee List
If you intend to use RSVP Registration:
Navigate to your Event Dashboard.
Click on Attendee List.
Add or upload your guests' email addresses to the list.
This ensures that only invited guests can register.
Option 2: Switch to Simple Registration
If you prefer to allow anyone to register:
Go to your Event Dashboard.
Select Setup > Registration.
Under the Setup tab, change the registration type to Simple Registration.
This setting permits open registration without requiring guests to be on a pre-approved list.