Fatal error: Uncaught Error: Call to undefined function add_action() in /home/cezarypiatek1990/public_html/testwordpressa/wp-includes/blocks/widget-group.php:55 Stack trace: #0 {main} thrown in /home/cezarypiatek1990/public_html/testwordpressa/wp-includes/blocks/widget-group.php on line 55