Fatal error: Uncaught Error: Call to undefined function add_filter() in /home/kacperg/public_html/kacpergr/wp-content/plugins/modula-best-grid-gallery/includes/troubleshoot/class-modula-troubleshooting.php:48 Stack trace: #0 /home/kacperg/public_html/kacpergr/wp-content/plugins/modula-best-grid-gallery/includes/troubleshoot/class-modula-troubleshooting.php(11): Modula_Troubleshooting->define_troubleshooting_admin_hooks() #1 /home/kacperg/public_html/kacpergr/wp-content/plugins/modula-best-grid-gallery/includes/troubleshoot/class-modula-troubleshooting.php(21): Modula_Troubleshooting->__construct() #2 /home/kacperg/public_html/kacpergr/wp-content/plugins/modula-best-grid-gallery/includes/troubleshoot/class-modula-troubleshooting.php(234): Modula_Troubleshooting::get_instance() #3 {main} thrown in /home/kacperg/public_html/kacpergr/wp-content/plugins/modula-best-grid-gallery/includes/troubleshoot/class-modula-troubleshooting.php on line 48