TypeError: 'NoneType' object is not subscriptable

[ae-utbm-sentry]

Sentry Issue: SITH3-B

TypeError: 'NoneType' object is not subscriptable
(4 additional frame(s) were not displayed)
...
  File "core/views/__init__.py", line 170, in dispatch
    return super(GenericContentPermissionMixinBuilder, self).dispatch(
  File "django/views/generic/base.py", line 98, in dispatch
    return handler(request, *args, **kwargs)
  File "counter/views.py", line 417, in post
    context = self.get_context_data(object=self.object)
  File "counter/views.py", line 691, in get_context_data
    kwargs["basket_total"] = self.sum_basket(self.request)
  File "counter/views.py", line 442, in sum_basket
    total += infos["price"] * infos["qty"]