Q:Video Not Loading

I’m a freshman here, and it’s my first time to learning LLM on deeplearning.ai. I use MAC m1 chip(2020) with chrome browser.At first, everything done well, I could see the jupyter notebook and the video. But days later I can’t see the video, the area turns to black square(but the code area remains stable.) I’ve tried some tips: like cleaning my cookies on the browser and re-log in to the website.But the problem exists, what can I do?

the frontend shows:{error: {json: {message: “Sandbox is not ready”, code: -32022,…}}}