Fatal error: Uncaught mysqli_sql_exception: Access denied for user 'root'@'localhost' (using password: NO) in /home/mocktestinghub/public_html/lib/Database.php:21 Stack trace: #0 /home/mocktestinghub/public_html/lib/Database.php(21): mysqli->__construct('localhost', 'root', '', 'db_exam') #1 /home/mocktestinghub/public_html/lib/Database.php(17): Database->connectDB() #2 /home/mocktestinghub/public_html/inc/header.php(12): Database->__construct() #3 /home/mocktestinghub/public_html/index.php(1): include('/home/mocktesti...') #4 {main} thrown in /home/mocktestinghub/public_html/lib/Database.php on line 21