After unable delete course from database it show the message like below
Debug info: MySQL server has gone away
SELECT COUNT(*)
FROM mdllj_backup_ids_temp b
JOIN mdllj_user u ON u.id = b.itemid
WHERE b.backupid = ?
AND b.itemname = 'userfinal'
AND u.mnethostid != ?
[array (
0 => 'ab2e109a519c823351d623c33a602fa6',
1 => '1',
)]
Error code: dmlreadexception
×Stack trace:
line 486 of /lib/dml/moodle_database.php: dml_read_exception thrown
line 1175 of /lib/dml/mysqli_native_moodle_database.php: call to moodle_database->query_end()
line 1558 of /lib/dml/moodle_database.php: call to mysqli_native_moodle_database->get_records_sql()
line 1631 of /lib/dml/moodle_database.php: call to moodle_database->get_record_sql()
line 1841 of /lib/dml/moodle_database.php: call to moodle_database->get_field_sql()
line 477 of /backup/util/dbops/backup_controller_dbops.class.php: call to moodle_database->count_records_sql()
line 1787 of /backup/moodle2/backup_stepslib.php: call to backup_controller_dbops::backup_includes_mnet_remote_users()
line 88 of /backup/util/plan/backup_structure_step.class.php: call to backup_main_structure_step->define_structure()
line 181 of /backup/util/plan/base_task.class.php: call to backup_structure_step->execute()
line 178 of /backup/util/plan/base_plan.class.php: call to base_task->execute()
line 120 of /backup/util/plan/backup_plan.class.php: call to base_plan->execute()
line 322 of /backup/controller/backup_controller.class.php: call to backup_plan->execute()
line 121 of /admin/tool/recyclebin/classes/category_bin.php: call to backup_controller->execute_plan()
line 185 of /admin/tool/recyclebin/lib.php: call to tool_recyclebin\category_bin->store_item()
line 4824 of /lib/moodlelib.php: call to tool_recyclebin_pre_course_delete()
line 67 of /course/delete.php: call to delete_course()
