Fatal error: Uncaught Error: Class "PKP\invitation\core\Invitation" not found in /var/www/html/lib/pkp/classes/invitation/invitations/registrationAccess/RegistrationAccessInvite.php:32 Stack trace: #0 {main} thrown in /var/www/html/lib/pkp/classes/invitation/invitations/registrationAccess/RegistrationAccessInvite.php on line 32