Can not execute event observer 'block_xp\local\observer\observer::catch_all'

• line 164 of /lib/classes/event/manager.php: call to debugging()
• line 75 of /lib/classes/event/manager.php: call to core\event\manager::process_buffers()
• line 834 of /lib/classes/event/base.php: call to core\event\manager::dispatch()
• line 4591 of /lib/moodlelib.php: call to core\event\base->trigger()
• line 2678 of /lib/moodlelib.php: call to complete_user_login()
• line 3162 of /lib/moodlelib.php: call to require_login()
• line 55 of /mod/glossary/print.php: call to require_course_login()