ReflectionException: The parameter class is expected to be either a string or an object in ReflectionMethod->__construct()

Problem/Motivation

При переходе на страницу /admin/config/system/fz152/contact ошибка:

ReflectionException: The parameter class is expected to be either a string or an object in ReflectionMethod->__construct() (line 53 of vendor/symfony/http-kernel/ControllerMetadata/ArgumentMetadataFactory.php).
Symfony\Component\HttpKernel\ControllerMetadata\ArgumentMetadataFactory->createArgumentMetadata(Array) (Line: 50)
Symfony\Component\HttpKernel\Controller\ArgumentResolver->getArguments(Object, Array) (Line: 83)
Drupal\Core\Controller\FormController->getContentResult(Object, Object)
call_user_func_array(Array, Array) (Line: 123)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 573)
Drupal\Core\Render\Renderer->executeInRenderContext(Object, Object) (Line: 124)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->wrapControllerExecutionInRenderContext(Array, Array) (Line: 97)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 151)
Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object, 1) (Line: 68)
Symfony\Component\HttpKernel\HttpKernel->handle(Object, 1, 1) (Line: 57)
Drupal\Core\StackMiddleware\Session->handle(Object, 1, 1) (Line: 47)
Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object, 1, 1) (Line: 106)
Drupal\page_cache\StackMiddleware\PageCache->pass(Object, 1, 1) (Line: 85)
Drupal\page_cache\StackMiddleware\PageCache->handle(Object, 1, 1) (Line: 47)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object, 1, 1) (Line: 52)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object, 1, 1) (Line: 23)
Stack\StackedHttpKernel->handle(Object, 1, 1) (Line: 708)
Drupal\Core\DrupalKernel->handle(Object) (Line: 19)

Steps to reproduce

Возможно, после создания новой контактной формы, пошёл в админку, узнать, почему не отображается на новой форме предупреждение об обработке пд.