Password resetter [] is not defined

Hello, When I go to Laravel's password reset link (example.com/password/reset), write my email and click "Send Password Reset Link" button, it goes to example.com/password/email link and gives an error:

[2018-07-21 17:59:35] local.ERROR: Password resetter [] is not defined. {"exception":"[object] (InvalidArgumentException(code: 0): Password resetter [] is not defined. at /var/www/project/vendor/laravel/framework/src/Illuminate/Auth/Passwords/PasswordBrokerManager.php:67)

I use Laravel 5.6 I should note that when I moved my Laravel project to new VPS, this error happened. I use laravel on my VPS. Whats the problem?