When I make a video I can see myself, but when I replay it for classmates there is sound but no images. Can anyone help me solve this problem?

When I click recording after a I make a video and click the URL for my recording I only get sound but no images, even thought I could see myself on the webcam in the box on the upper right side during the process of making my video. Tech support at my grad school could not figure it out. Can anyone help?