У меня есть две модели, как это:

class School(models.Model):
    name = models.CharField(max_length = 50)

    def __unicode__(self):
        return self.name 

class Education(models.Model):
    user_profile = models.ForeignKey(UserProfile, related_name='Education')
    school = models.OneToOneField(School)

    def __unicode__(self):
        return self.school

Когда я хочу добавить образование в userprofile с администратором django, эта ошибка eccour:

Traceback:
File "/usr/local/lib/python2.7/dist-packages/django/core/handlers/base.py" in get_response
  115.                         response = callback(request, *callback_args, **callback_kwargs)
File "/usr/local/lib/python2.7/dist-packages/django/contrib/admin/options.py" in wrapper
  372.                 return self.admin_site.admin_view(view)(*args, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/django/utils/decorators.py" in _wrapped_view
  91.                     response = view_func(request, *args, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/django/views/decorators/cache.py" in _wrapped_view_func
  89.         response = view_func(request, *args, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/django/contrib/admin/sites.py" in inner
  202.             return view(request, *args, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/django/utils/decorators.py" in _wrapper
  25.             return bound_func(*args, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/django/utils/decorators.py" in _wrapped_view
  91.                     response = view_func(request, *args, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/django/utils/decorators.py" in bound_func
  21.                 return func(self, *args2, **kwargs2)
File "/usr/local/lib/python2.7/dist-packages/django/db/transaction.py" in inner
  223.                 return func(*args, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/django/contrib/admin/options.py" in add_view
  1009.                 self.log_addition(request, new_object)
File "/usr/local/lib/python2.7/dist-packages/django/contrib/admin/options.py" in log_addition
  530.             action_flag     = ADDITION
File "/usr/local/lib/python2.7/dist-packages/django/contrib/admin/models.py" in log_action
  18.         e = self.model(None, None, user_id, content_type_id, smart_text(object_id), object_repr[:200], action_flag, change_message)

Exception Type: TypeError at /admin/social/education/add/
Exception Value: 'School' object has no attribute '__getitem__'

Как я могу исправить эту ошибку?