The same has happened to me.  What to do? 

The same just thing just happened to me. 

Hi Tracy,

It sounds like you might have accidentally logged into the wrong account---this is usually the reason why classes or progress seem to disappear. If you navigate to your Account Settings page, can you verify that this shows the correct email address and username for your account?

If you're using the Google sign-in option, then I suggest clearing your browser cache and then signing back in. This is one of the most frequent causes of missing progress, since it can be very easy to accidentally sign in using a personal account vs. a school account, for example.

If that doesn't work, please submit a support ticket so that we can further investigate the issue!

Same issue happened to me. I verified the correct email was being used and I also cleared the browser cache. I have submitted a support ticket.