@rande , but take a look at the condition:
(! in_array(getMappingType(), array(ONE_TO_ONE, MANY_TO_ONE )))
So this exception may throws for <code>ClassMetadataInfo::ONE_TO_MANY</code>.
But as was answered here: #160 <code>sonata_type_model_list</code> is only for toOne relations (and both of them can't pass the condition). So using it caused <code>No entity manager defined for class Doctrine\ORM\PersistentCollection</code> exception in case of one to many relation.
So <code>sonata_type_collection</code> is more prefer choice here, I think. Am I wrong?