Argument 1 passed to Illuminate\Auth\Guard::login() must implement interface Illuminate\Auth\UserInterface, null given open:

Argument 1 passed to Illuminate\Auth\Guard::login() must implement interface Illuminate\Auth\UserInterface, null given open:

in the create() method in the LoginController you must return the $user that worked for me

protected function create(array $data)
{
    $user = User::create([
        'username' => $data['username'],
        'email' => $data['email'],
        'password' => bcrypt($data['password']),
    ]);

    return $user;
}