Fatal error: Uncaught Error: Call to undefined function add_action() in /var/www/html/selimlab/wp-content/plugins/siteorigin-panels/settings/settings.php:20 Stack trace: #0 /var/www/html/selimlab/wp-content/plugins/siteorigin-panels/settings/settings.php(36): SiteOrigin_Panels_Settings->__construct() #1 /var/www/html/selimlab/wp-content/plugins/siteorigin-panels/settings/settings.php(543): SiteOrigin_Panels_Settings::single() #2 {main} thrown in /var/www/html/selimlab/wp-content/plugins/siteorigin-panels/settings/settings.php on line 20