Problem in creating answer form

sir it is showing this kind of error:
File “C:\Users\Rawat\Desktop\poller\env\lib\site-packages\django\forms\models.py”, line 242, in new
raise ImproperlyConfigured(
django.core.exceptions.ImproperlyConfigured: Creating a ModelForm without either the ‘fields’ attribute or the ‘exclude’ attribute is prohibited; form AnswerForm needs updating.