Fatal error: Uncaught Error: Call to undefined function add_action() in /home/kacperg/public_html/kacpergr/wp-content/plugins/jetpack/modules/infinite-scroll/themes/twentythirteen.php:18 Stack trace: #0 {main} thrown in /home/kacperg/public_html/kacpergr/wp-content/plugins/jetpack/modules/infinite-scroll/themes/twentythirteen.php on line 18