Fatal error: Uncaught Error: Call to undefined function add_action() in /home/clmepl5/public_html/web/app/plugins/the-events-calendar-shortcode/includes/ajax-endpoints.php:17 Stack trace: #0 {main} thrown in /home/clmepl5/public_html/web/app/plugins/the-events-calendar-shortcode/includes/ajax-endpoints.php on line 17