Fatal error: Uncaught Error: Call to undefined function add_action() in /home/kacperg/public_html/kacpergr/wp-content/plugins/modula-best-grid-gallery/includes/admin/class-modula-importer-exporter.php:18 Stack trace: #0 /home/kacperg/public_html/kacpergr/wp-content/plugins/modula-best-grid-gallery/includes/admin/class-modula-importer-exporter.php(195): Modula_Importer_Exporter->__construct() #1 {main} thrown in /home/kacperg/public_html/kacpergr/wp-content/plugins/modula-best-grid-gallery/includes/admin/class-modula-importer-exporter.php on line 18