Fatal error: Uncaught Error: Call to undefined function add_filter() in /home/ForrestPLK/public_html/mzktomaszow/wp-content/install/rockettheme/sample/data.php:29 Stack trace: #0 {main} thrown in /home/ForrestPLK/public_html/mzktomaszow/wp-content/install/rockettheme/sample/data.php on line 29