Fatal error: Uncaught Error: Call to undefined function add_action() in /home/imperfettolab/public_html/web/app/mu-plugins/advanced-custom-fields-pro/includes/upgrades.php:450 Stack trace: #0 {main} thrown in /home/imperfettolab/public_html/web/app/mu-plugins/advanced-custom-fields-pro/includes/upgrades.php on line 450