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 /home/misoul/public_html/wp-content/plugins/timetable/timetable.php(37): require_once('/home/misoul/pu...')
#2 {main}
thrown in /home/misoul/public_html/wp-content/plugins/timetable/timetable-shortcode.class.php on line 9