On our development server, I tried to click some quiz, but it gave me the following error message:
Found more than one record in fetch() !
More information about this error
line 429 of /lib/setuplib.php: moodle_exception thrown
line 146 of /lib/grade/grade_object.php: call to print_error()
line 316 of /lib/grade/grade_item.php: call to grade_object::fetch_helper()
line 947 of /lib/grade/grade_item.php: call to grade_item::fetch()
line 352 of /lib/gradelib.php: call to grade_item::fetch_course_item()
line 146 of /mod/quiz/view.php: call to grade_get_grades()
After the investigation, I found, there are duplicate "course" in the ITEMTYPE field in the GRADE_ITEM table. I know for each course, there should be only one "course" ITEMTYPE in this table. I am not sure what's the reason to create multiple ones, maybe by quiz backup/import, course backup/import, etc. I would like to attach those records, and let me know if you can find anything useful.