Fatal error: Uncaught Error: Call to undefined function add_action() in /home/marshalltowncsd/sites/marshalltown.k12.ia.us/releases/20230829083101/web/app/plugins/simple-page-ordering/simple-page-ordering.php:56 Stack trace: #0 /home/marshalltowncsd/sites/marshalltown.k12.ia.us/releases/20230829083101/web/app/plugins/simple-page-ordering/simple-page-ordering.php(39): Simple_Page_Ordering::add_actions() #1 /home/marshalltowncsd/sites/marshalltown.k12.ia.us/releases/20230829083101/web/app/plugins/simple-page-ordering/simple-page-ordering.php(606): Simple_Page_Ordering::get_instance() #2 {main} thrown in /home/marshalltowncsd/sites/marshalltown.k12.ia.us/releases/20230829083101/web/app/plugins/simple-page-ordering/simple-page-ordering.php on line 56