Unexpected Exception: SQLSTATE[HY000] [1045] Access denied for user ****@’localhost’ (using password: YES)

Sometimes Access denied Exception Error because your mysql credentials are invalid. Secondly, from my experience i observed that this also happens because you did not set password to your database connectivity. eg

private $host = "localhost";
private $db_name = "db_dbtest"; // Database name
private $username = "db_user"; // your database username
private $password = "db_password"; // Your password
public $conn;

}

Try and set password to your database connectivity. I had such experience and after changing my Collation to utf8_general_ci on the Operations tab, this could not solve my problem. I thought of adding password to my database connection and immediately it connected. You can tesrun this and see if it helps.