Catchable Fatal Error: Argument 4 passed to UsernamePasswordToken::__construct() must be an array, null given

Question

I am getting the following error when logging in into my Symfony application (with correct username and password):

ContextErrorException: Catchable Fatal Error: Argument 4 passed to Symfony\Component\Security\Core\Authentication\Token\UsernamePasswordToken::__construct() must be an array, null given, called in D:\xampp\htdocs\essweb\vendor\symfony\symfony\src\Symfony\Component\Security\Core\Authentication\Provider\UserAuthenticationProvider.php on line 96 and defined in D:\xampp\htdocs\essweb\vendor\symfony\symfony\src\Symfony\Component\Security\Core\Authentication\Token\UsernamePasswordToken.php line 36

Security.yml

firewalls:
        admin_area:
            pattern:    ^/
            anonymous: ~
            form_login:
                login_path:  /
                check_path:  /login_check
                default_target_path: /user
                failure_path: /
                #username_parameter: username
                #password_parameter: password
                remember_me: true

            remember_me:
                key: "%secret%"
                lifetime: 31536000
                path: /
                domain: ~
                always_remember_me: true
            logout:
                path:   /logout
                target: /  

Updated:

Login form:

<form class="form-signin form-group" action="{{ path('login_check') }}" method="post">
Username: <input type="text" class="form-control" name="_username" placeholder="Username" value="{{ last_username }}" required="required">
Password: <input type="text" class="form-control" name="_password" placeholder="" value="{{ last_username }}" required="required">
<button class="btn btn-sm btn-primary btn-block" type="submit">Sign in</button>

Answer 1

I fix this error so returning roles:

public function getRoles()
{
    return $this->roles->toArray();

}

Answer 2

Basically, what the error message says is:

The 4th argument for UsernamePasswordToken::__construct() should be an array, but it's null. It was called in UserAuthenticationProvider at line 96.

If you take a look at that code, you'll see that the 4th argument for UsernamePasswordToken::__construct() is $roles. So that should be an array, but it's getting null instead.

I'm guessing that you have written your own User entity, and that the getRoles() method of your user entity is returning null instead of an array of roles. So just change that method to something like this:

/**
 * Returns the roles granted to the user.
 * 
 * @return Role[] The user roles
 */
public function getRoles()
{
    return array('ROLE_USER');
}

Of course, the actual code may differ (you might want to store the user roles in the database), as long as getRoles() returns an array of strings or Role objects.