Video loads but doesn't play

I've been watching my college "class capture" for months.It's APRESO presentation of lectures. Now the video and audio loads but just says "ready" and doesn't play. Pushing the play button manually does nothing. Any help with this? Hard to do long distance learning!
Using Win7 on a laptop with WMP11. Using IE to access video. I've uninstalled and reinstalled WMP. I've reset IE.

Thanks for any help.