Steps to reproduce:

• Login to admin interface;
• Create an article object (Article 1);
• Create another article object (Article 2), embed Article 1 into an eZXML attribute - used "Body" - and publish;
• Article 1 was correctly embedded into Article 2;
• Delete Article 1;
• Display Article 2 in the frontend (new stack)

An error is displayed:

An exception has been thrown during the rendering of a template ("Could not find 'Content' with identifier 'array (
'id' => '126',
'languages' => NULL,
'versionNo' => NULL,
)'") in "EzPublishCoreBundle::content_fields.html.twig".