"message": "Unable to get a property on a non-object."?

Question

symfony

* @ParamConverter("importLegalEntity", converter="import_legal_entity")
* @Security("user.getId() === legalEntity.getOwnerIdValue()")

Registered in services_param_converter.yaml:

App\Infrastructure\Service\ParamConverter\ImportLegalEntityParamConverter:
        arguments:
            - '@infra.repo.import_legal_entity'
        tags:
            - { name: request.param_converter, converter: import_legal_entity }

Also services.yaml:

infra.repo.import_legal_entity:
        alias: 'App\Infrastructure\Repository\LegalEntityRepository'
        public: true

And
ImportLegalEntityParamConverter.php itself

<?php

namespace App\Infrastructure\Service\ParamConverter;

use App\Domain\Entity\LegalEntity;
use App\Domain\Repository\LegalEntityRepositoryInterface;
use Sensio\Bundle\FrameworkExtraBundle\Configuration\ParamConverter;
use Sensio\Bundle\FrameworkExtraBundle\Request\ParamConverter\ParamConverterInterface;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;

final class ImportLegalEntityParamConverter implements ParamConverterInterface
{
    /**
     * @var LegalEntityRepositoryInterface
     */
    private $legalEntityRepository;

    /**
     * LegalEntityParamConverter constructor.
     *
     * @param LegalEntityRepositoryInterface $legalEntityRepository
     */
    public function __construct(LegalEntityRepositoryInterface $legalEntityRepository)
    {
        $this->legalEntityRepository = $legalEntityRepository;
    }

    /**
     * @param Request        $request
     * @param ParamConverter $configuration
     *
     * @return bool|void
     *
     * @throws NotFoundHttpException
     */
    public function apply(Request $request, ParamConverter $configuration): bool
    {
        $legalEntity = null;
        $legalEntityId = null;

        if ($request->attributes->has('id')) {
            $legalEntityId = (int) $request->attributes->get('id');
        } elseif ($request->attributes->has('legalEntityId')) {
            $legalEntityId = (int) $request->attributes->get('legalEntityId');
        } elseif ($request->request->has('legalEntityId')) {
            $legalEntityId = (int) $request->request->get('legalEntityId');
        } elseif ($request->query->has('legalEntityId')) {
            $legalEntityId = (int) $request->query->get('legalEntityId');
        }

        if (null !== $legalEntityId) {
            $legalEntity = $this->legalEntityRepository->findById($legalEntityId);

            if (null === $legalEntity) {
                throw new NotFoundHttpException('generic.exception.legal_entity.not_exists');
            }
        }

        $request->attributes->set($configuration->getName(), $legalEntity);

        return true;
    }

    /**
     * @param ParamConverter $configuration
     *
     * @return bool
     */
    public function supports(ParamConverter $configuration)
    {
        return LegalEntity::class === $configuration->getClass();
    }
}

Part of the controller where I use ParamConverter:

* @ParamConverter("legalEntity", converter="legal_entity")
     *
     * @Security("(user.getGroupId() === legalEntity.getGroupIdValue() && legalEntity.isAlterable()) || user.getId() === legalEntity.getOwnerIdValue()")
     * @Security("null !== user.getPrivilege()")
     *
     * @param Request $request
     * @param LegalEntity $legalEntity
     *
     * @return JsonResponse
     *
     * @throws BirthdayInvalidException
     * @throws CivilityInvalidException
     * @throws DateInvalidException
     * @throws EmailInvalidException
     * @throws FeelingInvalidException
     * @throws GeoPointInvalidException
     * @throws LanguageInvalidException
     * @throws ModelException
     * @throws NotValidFormException
     * @throws OpportunityInvalidException
     * @throws PermissionInvalidException
     * @throws PhoneNumberInvalidException
     * @throws RoleInvalidException
     * @throws SituationInvalidException
     * @throws TypeInvalidException
     * @throws UserTokenInvalidException
     * @throws \App\Domain\Exception\Property\MainPictureInvalidException
     */
    public function importLegalEntityCreateAction(Request $request, LegalEntity $legalEntity): JsonResponse

I'm starting to work with @ParamConverter and everything seems to be done! right, but... here is the error:

{
  "message": "Unable to get a property on a non-object."
}