Fatal error: Uncaught mysqli_sql_exception: Access denied for user ''@'localhost' (using password: NO) in C:\xampp\htdocs\functions.php:10 Stack trace: #0 C:\xampp\htdocs\functions.php(10): mysqli_connect('', '', Object(SensitiveParameterValue), '') #1 C:\xampp\htdocs\register.php(7): DB_con->__construct() #2 {main} thrown in C:\xampp\htdocs\functions.php on line 10