JSON API POST 500 ERROR

Hi!

I want to post an article via Json API. When I install and enable module, post an article, the response is "201 Created" OK.

After that I install and enable JSON API File, with Token and File Entity module, because I want to upload image to article.
If this modules enabled, and POST an article with JSON API, I get 500 Internal Server Error, but the article created!

Version:
Drupal 8.5.4
PHP 7.1.18
Apache 2.4.6
MariaDb 10.3.7

The log details is:

TypeError: Argument 1 passed to Drupal\jsonapi\Normalizer\EntityReferenceFieldNormalizer::isInternalResourceType() must implement interface Drupal\Core\Entity\EntityInterface, null given, called in /var/www/html/lab01/modules/contrib/jsonapi/src/Normalizer/EntityReferenceFieldNormalizer.php on line 138 in Drupal\jsonapi\Normalizer\EntityReferenceFieldNormalizer->isInternalResourceType() (line 253 of /var/www/html/lab01/modules/contrib/jsonapi/src/Normalizer/EntityReferenceFieldNormalizer.php) #0 /var/www/html/lab01/modules/contrib/jsonapi/src/Normalizer/EntityReferenceFieldNormalizer.php(138): Drupal\jsonapi\Normalizer\EntityReferenceFieldNormalizer->isInternalResourceType(NULL) #1 /var/www/html/lab01/vendor/symfony/serializer/Serializer.php(143): Drupal\jsonapi\Normalizer\EntityReferenceFieldNormalizer->normalize(Object(Drupal\Core\Field\EntityReferenceFieldItemList), 'api_json', Array) #2 /var/www/html/lab01/modules/contrib/jsonapi/src/Serializer/Serializer.php(46): Symfony\Component\Serializer\Serializer->normalize(Object(Drupal\Core\Field\EntityReferenceFieldItemList), 'api_json', Array) #3 /var/www/html/lab01/modules/contrib/jsonapi/src/Normalizer/EntityNormalizer.php(214): Drupal\jsonapi\Serializer\Serializer->normalize(Object(Drupal\Core\Field\EntityReferenceFieldItemList), 'api_json', Array) #4 /var/www/html/lab01/modules/contrib/jsonapi/src/Normalizer/EntityNormalizer.php(99): Drupal\jsonapi\Normalizer\EntityNormalizer->serializeField(Object(Drupal\Core\Field\EntityReferenceFieldItemList), Array, 'api_json') #5 /var/www/html/lab01/modules/jsonapi_extras/src/Normalizer/EntityNormalizerTrait.php(72): Drupal\jsonapi\Normalizer\EntityNormalizer->normalize(Object(Drupal\node\Entity\Node), 'api_json', Array) #6 /var/www/html/lab01/vendor/symfony/serializer/Serializer.php(143): Drupal\jsonapi_extras\Normalizer\ContentEntityNormalizer->normalize(Object(Drupal\node\Entity\Node), 'api_json', Array) #7 /var/www/html/lab01/modules/contrib/jsonapi/src/Serializer/Serializer.php(46): Symfony\Component\Serializer\Serializer->normalize(Object(Drupal\node\Entity\Node), 'api_json', Array) #8 /var/www/html/lab01/modules/contrib/jsonapi/src/Normalizer/JsonApiDocumentTopLevelNormalizer.php(218): Drupal\jsonapi\Serializer\Serializer->normalize(Object(Drupal\node\Entity\Node), 'api_json', Array) #9 [internal function]: Drupal\jsonapi\Normalizer\JsonApiDocumentTopLevelNormalizer->Drupal\jsonapi\Normalizer\{closure}(Object(Drupal\node\Entity\Node)) #10 /var/www/html/lab01/modules/contrib/jsonapi/src/Normalizer/JsonApiDocumentTopLevelNormalizer.php(219): array_map(Object(Closure), Array) #11 /var/www/html/lab01/modules/contrib/jsonapi/src/Normalizer/JsonApiDocumentTopLevelNormalizer.php(172): Drupal\jsonapi\Normalizer\JsonApiDocumentTopLevelNormalizer->buildNormalizerValue(Object(Drupal\node\Entity\Node), 'api_json', Array) #12 /var/www/html/lab01/vendor/symfony/serializer/Serializer.php(143): Drupal\jsonapi\Normalizer\JsonApiDocumentTopLevelNormalizer->normalize(Object(Drupal\jsonapi\Resource\JsonApiDocumentTopLevel), 'api_json', Array) #13 /var/www/html/lab01/modules/contrib/jsonapi/src/Serializer/Serializer.php(46): Symfony\Component\Serializer\Serializer->normalize(Object(Drupal\jsonapi\Resource\JsonApiDocumentTopLevel), 'api_json', Array) #14 /var/www/html/lab01/vendor/symfony/serializer/Serializer.php(116): Drupal\jsonapi\Serializer\Serializer->normalize(Object(Drupal\jsonapi\Resource\JsonApiDocumentTopLevel), 'api_json', Array) #15 /var/www/html/lab01/modules/contrib/jsonapi/src/EventSubscriber/ResourceResponseSubscriber.php(140): Symfony\Component\Serializer\Serializer->serialize(Object(Drupal\jsonapi\Resource\JsonApiDocumentTopLevel), 'api_json', Array) #16 /var/www/html/lab01/core/lib/Drupal/Core/Render/Renderer.php(582): Drupal\jsonapi\EventSubscriber\ResourceResponseSubscriber->Drupal\jsonapi\EventSubscriber\{closure}() #17 /var/www/html/lab01/modules/contrib/jsonapi/src/EventSubscriber/ResourceResponseSubscriber.php(143): Drupal\Core\Render\Renderer->executeInRenderContext(Object(Drupal\Core\Render\RenderContext), Object(Closure)) #18 /var/www/html/lab01/modules/contrib/jsonapi/src/EventSubscriber/ResourceResponseSubscriber.php(93): Drupal\jsonapi\EventSubscriber\ResourceResponseSubscriber->renderResponseBody(Object(Symfony\Component\HttpFoundation\Request), Object(Drupal\jsonapi\ResourceResponse), Object(Drupal\jsonapi\Serializer\Serializer), 'api_json') #19 [internal function]: Drupal\jsonapi\EventSubscriber\ResourceResponseSubscriber->onResponse(Object(Symfony\Component\HttpKernel\Event\FilterResponseEvent), 'kernel.response', Object(Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher)) #20 /var/www/html/lab01/core/lib/Drupal/Component/EventDispatcher/ContainerAwareEventDispatcher.php(111): call_user_func(Array, Object(Symfony\Component\HttpKernel\Event\FilterResponseEvent), 'kernel.response', Object(Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher)) #21 /var/www/html/lab01/vendor/symfony/http-kernel/HttpKernel.php(191): Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch('kernel.response', Object(Symfony\Component\HttpKernel\Event\FilterResponseEvent)) #22 /var/www/html/lab01/vendor/symfony/http-kernel/HttpKernel.php(173): Symfony\Component\HttpKernel\HttpKernel->filterResponse(Object(Drupal\jsonapi\ResourceResponse), Object(Symfony\Component\HttpFoundation\Request), 1) #23 /var/www/html/lab01/vendor/symfony/http-kernel/HttpKernel.php(68): Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object(Symfony\Component\HttpFoundation\Request), 1) #24 /var/www/html/lab01/core/lib/Drupal/Core/StackMiddleware/Session.php(57): Symfony\Component\HttpKernel\HttpKernel->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true) #25 /var/www/html/lab01/core/lib/Drupal/Core/StackMiddleware/KernelPreHandle.php(47): Drupal\Core\StackMiddleware\Session->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true) #26 /var/www/html/lab01/core/modules/page_cache/src/StackMiddleware/PageCache.php(99): Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true) #27 /var/www/html/lab01/core/modules/page_cache/src/StackMiddleware/PageCache.php(78): Drupal\page_cache\StackMiddleware\PageCache->pass(Object(Symfony\Component\HttpFoundation\Request), 1, true) #28 /var/www/html/lab01/modules/contrib/jsonapi/src/StackMiddleware/FormatSetter.php(41): Drupal\page_cache\StackMiddleware\PageCache->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true) #29 /var/www/html/lab01/core/lib/Drupal/Core/StackMiddleware/ReverseProxyMiddleware.php(47): Drupal\jsonapi\StackMiddleware\FormatSetter->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true) #30 /var/www/html/lab01/core/lib/Drupal/Core/StackMiddleware/NegotiationMiddleware.php(52): Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true) #31 /var/www/html/lab01/vendor/stack/builder/src/Stack/StackedHttpKernel.php(23): Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true) #32 /var/www/html/lab01/core/lib/Drupal/Core/DrupalKernel.php(666): Stack\StackedHttpKernel->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true) #33 /var/www/html/lab01/index.php(19): Drupal\Core\DrupalKernel->handle(Object(Symfony\Component\HttpFoundation\Request)) #34 {main}.

Many Thanks!