Станислав Почепко

500 - jшибка в коде. Что в логах? Какой результат ответа?

url()

laravel.su/docs/5.0/database#read-write-connections

'mysql' => [
            'driver' => 'mysql',
            'host' => env('DB_HOST', 'https://my-site.com/'),
            'port' => env('DB_PORT', ''),
            'database' => env('DB_DATABASE', 'my_name'),
            'username' => env('DB_USERNAME', 'my_name'),
            'password' => env('DB_PASSWORD', 'my_pas'),
            'charset' => 'utf8',
            'collation' => 'utf8_unicode_ci',
            'prefix' => '',
            'strict' => true,
            'engine' => null,
        ],
'mysql2' => [
            'driver' => 'mysql',
            'host' => env('DB_HOST', 'https://my-site2.com/'),
            'port' => env('DB_PORT', ''),
            'database' => env('DB_DATABASE', 'my_name2'),
            'username' => env('DB_USERNAME', 'my_name3'),
            'password' => env('DB_PASSWORD', 'my_pas4'),
            'charset' => 'utf8',
            'collation' => 'utf8_unicode_ci',
            'prefix' => '',
            'strict' => true,
            'engine' => null,
        ],

laravel.su/docs/5.0/database#accessing-connections

DB::connection('mysql')->table('...')->get(); // Выбор из первого соединения
DB::connection('mysql2')->table('...')->get(); // Выбор из второго соединения

Вы это используете в конструкторе контроллера?

https://laravel.com/docs/5.3/upgrade

Session In The Constructor
In previous versions of Laravel, you could access session variables or the authenticated user in your controller's constructor. This was never intended to be an explicit feature of the framework. In Laravel 5.3, you can't access the session or authenticated user in your controller's constructor because the middleware has not run yet.
As an alternative, you may define a Closure based middleware directly in your controller's constructor. Before using this feature, make sure that your application is running Laravel 5.3.4 or above:

Скорее всего вам необходимо сделать обычный вызов соседнего метода

function foo(Request $request) {
    return $this->bar($request);
}

function bar(Request $request) {

// Your code
    return ...;
}

Route::get('films/form/{id?}', 'FilmsController@getForm');

laravel.su/docs/5.0/routing#route-parameters