The relation has multiple target fields, but only single target field was asked for

Raise code

et_field(self):
        """
        When filtering against this relation, return the field on the remote
        model against which the filtering should happen.
        """
        target_fields = self.get_path_info()[-1].target_fields
        if len(target_fields) > 1:
            raise exceptions.FieldError(
                "The relation has multiple target fields, but only single target field was asked for")
        return target_fields[0]

    def get_cache_name(self):
        return self.name


class Foreig