Fatal error: Uncaught Error: Call to undefined function add_action() in /home/difaluxelt/v3/wp-content/plugins/yith-woocommerce-frequently-bought-together/plugin-fw/lib/promo/yith-promo.php:15 Stack trace: #0 {main} thrown in /home/difaluxelt/v3/wp-content/plugins/yith-woocommerce-frequently-bought-together/plugin-fw/lib/promo/yith-promo.php on line 15