AttributeError at /8/1/ This QueryDict instance is immutable in django rating app

[techiekamran]

I am using start-rating library in my django application then i am getting this error. Please anyone tell me how to solve it.
--------------------------------------------------------- this is my model.py in testapp application in my project

class Test(models.Model):
name = models.ForeignKey(CustomUser,on_delete=models.CASCADE)
subject = models.CharField(max_length=30)
ratings = GenericRelation(Rating, related_query_name='test')

class TestCreate(LoginRequiredMixin,CreateView):
login_url = '/login/'
model = Test
fields = 'all'
success_url = '/'
template_name = 'testapp/test.html'

class TestList(ListView):
model = Test
template_name = 'testapp/test_list.html'

class TestDetails(DetailView):
model = Test
template_name = 'testapp/test_details.html'

this is my setting.py file

INSTALLED_APPS = [
'django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.messages',
'django.contrib.staticfiles',
'users',
'testapp',
'star_ratings',
]

Here my test_details.html file where i am getting error
   <ul>
  
 <li>{{ object.subject }}</li>
{% ratings object %}
   
</ul>

please any one tell me solution?
please tell me how to solve