Traceback (most recent call last):
  File "/home/pavel/work/npoed/npoed-plp-edx/npoed_plp/plp/views/datatables/base.py", line 287, in get_context_data
    qs = self.get_paged_queryset()
  File "/home/pavel/work/npoed/npoed-plp-edx/npoed_plp/plp/views/datatables/base.py", line 190, in get_paged_queryset
    qs = self.paging(self.get_ordered_queryset())
  File "/home/pavel/work/npoed/npoed-plp-edx/npoed_plp/plp/views/datatables/base.py", line 182, in get_ordered_queryset
    qs = self.get_filtered_queryset()
  File "/home/pavel/work/npoed/npoed-plp-edx/npoed_plp/plp/views/datatables/base.py", line 174, in get_filtered_queryset
    qs = self.get_annotated_queryset()
  File "/home/pavel/work/npoed/npoed-plp-edx/npoed_plp/plp/views/datatables/base.py", line 168, in get_annotated_queryset
    return self.get_initial_queryset().annotate(**anno)
  File "/home/pavel/work/npoed/npoed-plp-edx/npoed_plp/plp/views/analytics.py", line 486, in get_initial_queryset
    view_mode=self.get_view_mode_for_filter(self.request.user)
  File "/home/pavel/work/npoed/npoed-plp-edx/npoed_plp/plp/views/analytics.py", line 476, in get_view_mode_for_filter
    return get_view_mode_for_filter(self.university, self.form.cleaned_data.get("session").course, user)
AttributeError: 'NoneType' object has no attribute 'course'