Invalid get_string() identifier: 'summaryof' or component 'moodle'. Perhaps you are missing $string['summaryof'] = ''; in lang/en/moodle.php?

• line 355 of /lib/classes/string_manager_standard.php: call to debugging()
• line 6981 of /lib/moodlelib.php: call to core_string_manager_standard->get_string()
• line 58 of /course/info.php: call to get_string()