Customizing a Modal

I can’t update a dabasebase before overriding Country Modal a system returned this error

In MappingException.php line 340:

Class “AppBundle\Entity\Country” sub class of “Sylius\Component\Addressing
Model\Country” is not a valid entity or mapped super class.

i was defined a Country.orm.yml

note: it is a same exemple in the doc

http://docs.sylius.com/en/1.2/customization/model.html