Drupal 8 Preview Node Breaking Before Save

Question

I'm getting the following error when attempting to preview a node prior to saving :

The website encountered an unexpected error. Please try again later.

Drupal\Core\Entity\EntityMalformedException: The "node" entity cannot have a URI as it does not have an ID in Drupal\Core\Entity\Entity->toUrl() (line 179 of core/lib/Drupal/Core/Entity/Entity.php).
Drupal\Core\Entity\Entity->urlInfo('revision') (Line: 120)
Drupal\Core\Field\Plugin\Field\FieldFormatter\StringFormatter->viewElements(Object, 'en') (Line: 80)
Drupal\Core\Field\FormatterBase->view(Object, 'en') (Line: 259)
Drupal\Core\Entity\Entity\EntityViewDisplay->buildMultiple(Array) (Line: 320)
Drupal\Core\Entity\EntityViewBuilder->buildComponents(Array, Array, Array, 'full') (Line: 24)
Drupal\node\NodeViewBuilder->buildComponents(Array, Array, Array, 'full') (Line: 263)
Drupal\Core\Entity\EntityViewBuilder->buildMultiple(Array) (Line: 220)
Drupal\Core\Entity\EntityViewBuilder->build(Array)
call_user_func(Array, Array) (Line: 376)
Drupal\Core\Render\Renderer->doRender(Array, ) (Line: 195)
Drupal\Core\Render\Renderer->render(Array, ) (Line: 226)
Drupal\Core\Render\MainContent\HtmlRenderer->Drupal\Core\Render\MainContent\{closure}() (Line: 574)
Drupal\Core\Render\Renderer->executeInRenderContext(Object, Object) (Line: 227)
Drupal\Core\Render\MainContent\HtmlRenderer->prepare(Array, Object, Object) (Line: 117)
Drupal\Core\Render\MainContent\HtmlRenderer->renderResponse(Array, Object, Object) (Line: 90)
Drupal\Core\EventSubscriber\MainContentViewSubscriber->onViewRenderArray(Object, 'kernel.view', Object) (Line: 111)
Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch('kernel.view', Object) (Line: 149)
Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object, 1) (Line: 64)
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: 99)
Drupal\page_cache\StackMiddleware\PageCache->pass(Object, 1, 1) (Line: 78)
Drupal\page_cache\StackMiddleware\PageCache->handle(Object, 1, 1) (Line: 47)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object, 1, 1) (Line: 50)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object, 1, 1) (Line: 23)
Stack\StackedHttpKernel->handle(Object, 1, 1) (Line: 656)
Drupal\Core\DrupalKernel->handle(Object) (Line: 19)

I've seen errors like this patched (in that case it was a Disqus Comment issue, which we don't use). I was wondering if anyone else had this issue in Drupal 8?

Mike

Answer 1

It seems your content type has a text field with "Plain text" formatter with "Link to the node" option in "Full" view mode. It tries to build a link to the new node when you preview it, and fails (of course, because node id is required to build a link, but it is not set until you save the node).

I don't think there is any reason to have links to current node in "Full" view mode (because such links refer the same node page), so just uncheck "Link to the node" option in your field settings.