Perhaps this works within the same institution. If you are sharing across commons between institutions (e.g. you're part-time faculty at two colleges) this doesn't work. I guess if I want to use the video quiz that I created at one college in the same class at my other college, I have to share the video (or just upload the .mp4 to my other Studio) and then recreate the quiz questions, from scratch! Bummer!!!!! I was getting really excited about video quizzes, but this makes me reluctant to use them in the future, knowing that I'll have to re-do so much work.