Study.DoesNotExist: Study matching query does not exist.

[sentry-io]

Sentry Issue: EDUCATION-BACKEND-4T

Study.DoesNotExist: Study matching query does not exist.
(4 additional frame(s) were not displayed)
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  File "diplomas/services/diploma_generator.py", line 65, in get_external_service_url
    return urljoin(settings.DIPLOMA_GENERATOR_HOST, f'/{self.template.slug}.png')
  File "diplomas/services/diploma_generator.py", line 41, in template
    homework_accepted=self.study.homework_accepted,
  File "diplomas/services/diploma_generator.py", line 34, in study
    return Study.objects.get(student=self.student, course=self.course)
  File "django/db/models/manager.py", line 85, in manager_method
    return getattr(self.get_queryset(), name)(*args, **kwargs)
  File "django/db/models/query.py", line 435, in get
    raise self.model.DoesNotExist(