I have created test build with vendors in https://github.com/butt/testSonata
"doctrine/orm": ">=2.2.3,<2.4-dev",
"doctrine/doctrine-bundle": "1.2.*",
"sonata-project/admin-bundle": "2.2.7",
"sonata-project/doctrine-orm-admin-bundle": "master-dev"
In order to reproduce bug you will need to create local copy, create a couple entities and open admin edit page for entity /admin/acme/demo/author/1/edit
screenshot attached