设置CreateBundle - 文档不受管理且没有ID

Question

I'm trying to set up and make working the CreateBundle but ran into this error:

An exception has been thrown during the rendering of a template ("Document is not managed and has no id: Ist1\PageBundle\Entity\Page@0000000019ffdaf900007f0da4032c17") in src/Ist1/PageBundle/Resources/views/Page/show.html.twig at line 18.

I've got a regular doctrine entity (Page), don't know if needed something else or ...? All I want is to be able to use the in-place editor for my Page entity.

rdf-mappings/Ist1.PageBundle.Entity.Page.xml:

<type xmlns:schema="http://schema.org/" typeof="schema:Page">
<children>
    <property property="schema:content" identifier="content"/>
</children>

The exception is thrown in the Doctrine\ODM\PHPCR\UnitOfWork class, as there is no key/value in the documentIds array for my page entity ...

if (empty($this->documentIds[$oid])) {
...