Plugin Events Manager 5.3

Ik krijg deze code als ik een evenement wil aanmaken, dit is pas als ik de laatste versie heb geinstalleerd van Events Manager

Warning: Missing argument 2 for get_post_meta(), called in /customers/0/6/a/canicross-info.eu/httpd.www/wp-content/plugins/events-manager/classes/em-event.php on line 329 and defined in /customers/0/6/a/canicross-info.eu/httpd.www/wp-includes/post.php on line 1465 Warning: Missing argument 2 for get_post_meta(), called in /customers/0/6/a/canicross-info.eu/httpd.www/wp-content/plugins/events-manager/classes/em-event.php on line 329 and defined in /customers/0/6/a/canicross-info.eu/httpd.www/wp-includes/post.php on line 1465