If you are just seeing green video when running your camera and sound check, this, unfortunately, means it has encountered an error. This issue has been caused by a recent Chrome update that we, alas, have no control over.
In order to ensure that this does not occur again, please go through the following steps on your computer:
Please copy and paste chrome://flags/#disable-accelerated-video-encode into your URL bar (or go to Settings in Google Chrome (The 3 dots/ellipses at the top right of the Chrome window). Then type "hardware" in the search bar at the top.
This will show the "Hardware-accelerated video encode" or "Use hardware acceleration when available" setting. If this is already toggled on, please switch it off. If it is turned off, please switch it on. To apply the changes, please restart Chrome.
This should prevent the issue from occurring again!