Close any other tabs or apps you may have open that are using your camera
Close other tabs running Google Meet
Remove Grid View Extension using Manage Extensions
Try a different device (Android phone, iPhone, or a different computer)
This can happen if the Meet is based out of Google Classroom and you have NOT accepted the Classroom Invite. Check you email for the classroom invite, if it is missing or expired please contact your teacher.
You are logged in with your personal Gmail account! Switch to your school provided @k12.kpdsb.ca account.