I am sorry to read that you are experiencing issues viewing videos in your course. Unfortunately, this issue is difficult to diagnose here in the Canvas Community website because most people here do not have access to your school's Canvas environment or your course. Have you tried contacting your instructor to see if he/she can help figure out what might be going on with those videos? It might be that the videos are not linked correctly in the course. However, that would be a question for your instructor. You can contact your instructor by following the steps in this Guide: