Stackoverflow appendix: Translatable doctrine array fieds

[1] Doctrine\DBAL\Types\ConversionException: Could not convert database value "" to Doctrine Type array
    at n/a
        in vendor/doctrine/dbal/lib/Doctrine/DBAL/Types/ConversionException.php line 46

    at Doctrine\DBAL\Types\ConversionException::conversionFailed('', 'array')
        in vendor/doctrine/dbal/lib/Doctrine/DBAL/Types/ArrayType.php line 60

    at Doctrine\DBAL\Types\ArrayType->convertToPHPValue('', object(MySqlPlatform))
        in vendor/gedmo/doctrine-extensions/lib/Gedmo/Translatable/Mapping/Event/Adapter/ORM.php line 225

    at Gedmo\Translatable\Mapping\Event\Adapter\ORM->setTranslationValue(object(Product), 'categories', '')
        in vendor/gedmo/doctrine-extensions/lib/Gedmo/Translatable/TranslatableListener.php line 473

    at Gedmo\Translatable\TranslatableListener->postLoad(object(LifecycleEventArgs))
        in vendor/symfony/symfony/src/Symfony/Bridge/Doctrine/ContainerAwareEventManager.php line 61

    at Symfony\Bridge\Doctrine\ContainerAwareEventManager->dispatchEvent('postLoad', object(LifecycleEventArgs))
        in vendor/doctrine/orm/lib/Doctrine/ORM/Event/ListenersInvoker.php line 117

    at Doctrine\ORM\Event\ListenersInvoker->invoke(object(ClassMetadata), 'postLoad', object(Product), object(LifecycleEventArgs), '4')
        in vendor/doctrine/orm/lib/Doctrine/ORM/UnitOfWork.php line 2743

    at Doctrine\ORM\UnitOfWork->createEntity('Acme\ExampleBundle\Entity\Product', array('categories' => null))
        in vendor/doctrine/orm/lib/Doctrine/ORM/Internal/Hydration/ObjectHydrator.php line 286

    at Doctrine\ORM\Internal\Hydration\ObjectHydrator->getEntity(array('categories' => null), 'r')
        in vendor/doctrine/orm/lib/Doctrine/ORM/Internal/Hydration/ObjectHydrator.php line 534

    at Doctrine\ORM\Internal\Hydration\ObjectHydrator->hydrateRowData(array('categories2' => 'N;'), 'categories2' => array('fieldName' => 'categories', 'type' => object(ArrayType), 'isIdentifier' => false, 'dqlAlias' => 'r')), array())
        in vendor/doctrine/orm/lib/Doctrine/ORM/Internal/Hydration/ObjectHydrator.php line 179

    at Doctrine\ORM\Internal\Hydration\ObjectHydrator->hydrateAllData()
        in vendor/doctrine/orm/lib/Doctrine/ORM/Internal/Hydration/AbstractHydrator.php line 140

    at Doctrine\ORM\Internal\Hydration\AbstractHydrator->hydrateAll(object(PDOStatement), object(ResultSetMapping), array('doctrine.refresh' => true))
        in vendor/doctrine/orm/lib/Doctrine/ORM/Persisters/BasicEntityPersister.php line 855

    at Doctrine\ORM\Persisters\BasicEntityPersister->refresh(array('id' => '3'), object(Product))
        in vendor/doctrine/orm/lib/Doctrine/ORM/UnitOfWork.php line 2059

    at Doctrine\ORM\UnitOfWork->doRefresh(object(Product), array('00000000400c5cde00006f97979828ad' => object(Product)))
        in vendor/doctrine/orm/lib/Doctrine/ORM/UnitOfWork.php line 2027

    at Doctrine\ORM\UnitOfWork->refresh(object(Product))
        in vendor/doctrine/orm/lib/Doctrine/ORM/EntityManager.php line 668

    at Doctrine\ORM\EntityManager->refresh(object(Product))
        in src/Acme/ExampleBundle/Controller/ProductController.php line 43

    at Acme\ExampleBundle\Controller\ProductController->showAction(object(Request), '3', 'fr')
        in  line

    at call_user_func_array(array(object(ProductController), 'showAction'), array(object(Request), '3', 'fr'))
        in app/bootstrap.php.cache line 2976

    at Symfony\Component\HttpKernel\HttpKernel->handleRaw(object(Request), '1')
        in app/bootstrap.php.cache line 2938

    at Symfony\Component\HttpKernel\HttpKernel->handle(object(Request), '1', true)
        in app/bootstrap.php.cache line 3087

    at Symfony\Component\HttpKernel\DependencyInjection\ContainerAwareHttpKernel->handle(object(Request), '1', true)
        in app/bootstrap.php.cache line 2337

    at Symfony\Component\HttpKernel\Kernel->handle(object(Request))
        in web/app_dev.php line 28