Datenbankfehler No identifier/primary key specified for Entity

Ich wollte die Datenbank migrieren und bekomme jetzt diesen Fehler. Kann mir jemand einen Tipp geben, woich suchen muss:

Fatal error : Uncaught exception ‘Doctrine\ORM\Mapping\MappingException’ with message ‘No identifier/primary key specified for Entity “Shopware\Models\Attribute\Article” sub class of “Shopware\Components\Model\ModelEntity”. Every Entity must have an identifier/primary key.’ in /xxx/vendor/doctrine/orm/lib/Doctrine/ORM/Mapping/MappingException.php:46 Stack trace: #0 /xxx/vendor/doctrine/orm/lib/Doctrine/ORM/Mapping/ClassMetadataInfo.php(1009): Doctrine\ORM\Mapping\MappingException::identifierRequired(‘Shopware\Models…’) #1 /xxx/vendor/doctrine/orm/lib/Doctrine/ORM/Mapping/ClassMetadataFactory.php(271): Doctrine\ORM\Mapping\ClassMetadataInfo->validateIdentifier() #2 /xxx/vendor/doctrine/orm/lib/Doctrine/ORM/Mapping/ClassMetadataFactory.php(251): Doctrine\ORM\Mapping\ClassMetadataFactory->validateRuntimeMetadata(Object(Doctrine\ORM\Mapping\ClassMetadata), NULL) #3 /xxx/vendor in /xxx/vendor/doctrine/orm/lib/Doctrine/ORM/Mapping/MappingException.php on line 46