Fatal error: Uncaught Error: Call to undefined function add_shortcode() in /home/misoul/public_html/wp-content/plugins/timetable/timetable-shortcode.class.php:9 Stack trace: #0 /home/misoul/public_html/wp-content/plugins/timetable/timetable-shortcode.class.php(3): TimetableShortcode->__construct() #1 {main} thrown in /home/misoul/public_html/wp-content/plugins/timetable/timetable-shortcode.class.php on line 9