Group Participant records associated with Default Contact should be updated to an actual Contact.
For more information about how these get created in your system, see Default Contacts.
The Customer Portal Report Card gives an A grade when you have a decrease of at least 5% from previous month (or none). The number counted is Group Participant records associated with Default Contact.
Assign Participant Tool: This tool is able to help assign a Contact with the Group Participant if it is associated with an Event. See Assign Participant Tool.
Default Field List: Ensure that you do not use a subquery in the Default Field List of the Group Participants page record. Doing so can cause errors for Group Signup in the Group Details widget.
Portal Configuration: See Portal Login/Authentication.
Views and Notifications: See Views.