Fatal error: Uncaught Error: Call to undefined function add_filter() in /home/kacperg/public_html/kacpergr/wp-content/plugins/modula-best-grid-gallery/includes/compatibility/class-modula-compatibility.php:22 Stack trace: #0 /home/kacperg/public_html/kacpergr/wp-content/plugins/modula-best-grid-gallery/includes/compatibility/class-modula-compatibility.php(41): Modula_Compatibility->__construct() #1 /home/kacperg/public_html/kacpergr/wp-content/plugins/modula-best-grid-gallery/includes/compatibility/class-modula-compatibility.php(292): Modula_Compatibility::get_instance() #2 {main} thrown in /home/kacperg/public_html/kacpergr/wp-content/plugins/modula-best-grid-gallery/includes/compatibility/class-modula-compatibility.php on line 22