Ошибка при переходе по вкладкам всех кроме суперюзера

class Customer(models.Model):
    user = models.OneToOneField(User, null=True, blank=True, on_delete=models.CASCADE,related_name="customer")
    name = models.CharField(max_length=200, null=True)
    email = models.CharField(max_length=200)
 
    def __str__(self):
        return self.name

class RegisterForm(UserCreationForm):
    class Meta(UserCreationForm.Meta):
        model = User
        fields = UserCreationForm.Meta.fields + ('email',)

@login_required
def profile_view(request):
    return render(request, 'registration/profile.html')
 
def login(request):
    return render(request, 'registration/login.html')
 
 
class RegisterView(FormView):
    form_class = RegisterForm
    template_name = 'registration/register.html'
    success_url = reverse_lazy('profile_view')
 
    def form_valid(self, form):
        form.save()
        return super().form_valid(form)

    def form_valid(self, form):
        form.save()
        Customer.objects.create(user=form.cleaned_data['username'], name=form.cleaned_data['first_name'], email=form.cleaned_data['email'])
        return super().form_valid(form)

user=form.cleaned_data['username']