Fatal error: Uncaught Error: Call to undefined function admin_url() in /home/dennis91/public_html/wp-content/plugins/events-calendar-pro/src/admin-views/manager/page.php:18
Stack trace:
#0 {main}
thrown in /home/dennis91/public_html/wp-content/plugins/events-calendar-pro/src/admin-views/manager/page.php on line 18