i'm trying to debugging and here is the list :
Warning: Invalid argument supplied for foreach() in D:\xampp\htdocs\moodle\mod\quiz\report\reportlib.php on line 26
Notice: Undefined index: 11377 in D:\xampp\htdocs\moodle\mod\quiz\report\overview\report.php on line 554
Notice: Trying to get property of non-object in D:\xampp\htdocs\moodle\lib\questionlib.php on line 1042
and on... for each number of question....