I've have a testing site recently upgraded from 1.9 to the HEAD. Entering into quiz I constantly see warning: Did you remember to make the first column something unique in your call to get_records? Duplicate value 'statistics' found in column 'name'. line 665 of \lib\dml\mysqli_native_moodle_database.php: call to debugging() line 1041 of \lib\dml\moodle_database.php: call to mysqli_native_moodle_database->get_records_sql() line 990 of \lib\dml\moodle_database.php: call to moodle_database->get_records_select() line 356 of \mod\quiz\report\reportlib.php: call to moodle_database->get_records() line 1464 of \mod\quiz\lib.php: call to quiz_report_list() line 2951 of \lib\navigationlib.php: call to quiz_extend_settings_navigation() line 2385 of \lib\navigationlib.php: call to settings_navigation->load_module_settings() line 485 of \lib\pagelib.php: call to settings_navigation->initialise() line 500 of \lib\pagelib.php: call to moodle_page->get_settingsnav() line 124 of \blocks\settings_navigation_tree\block_settings_navigation_tree.php: call to moodle_page->__get() line 832 of \blocks\moodleblock.class.php: call to block_settings_navigation_tree->get_content() line 364 of \blocks\moodleblock.class.php: call to block_tree->formatted_contents() line 803 of \lib\blocklib.php: call to block_base->get_content_for_output() line 862 of \lib\blocklib.php: call to block_manager->create_block_contents() line 314 of \lib\blocklib.php: call to block_manager->ensure_content_created() line 819 of \lib\outputrenderers.php: call to block_manager->region_has_content() line 700 of \lib\outputrenderers.php: call to moodle_core_renderer->handle_legacy_theme() line 89 of \mod\quiz\view.php: call to moodle_core_renderer->header() Looking in a database I found that quiz_report table contains two entry for statistics report, some fields are different 1) cron =0, capability=NULL 2) cron=18000, capability=quizreport/statistics:view