As the post states, best practice is to always set your quizzes to "When time expires, submit automatically". This avoids the whole scenario from ever happening. I can confirm that post referenced above does work to allow the student or system administrator to submit the quiz. The quiz will then auto-grade and enter that grade in the corresponding grade book column.
Quiz
Quiz Never Submitted
اس بحث کو بند کر دیا گیا ہے لہذا آپ اس کا مزید جواب نہیں دے سکتے۔