your session has been disconnected

Can't run any of the tutorials here, tried in Chrome and Firefox.

I had the same issue. Fixed it by logging in on datacamp.

Click on the "Powered by DataCamp" below any of the examples, and create an account. If you don't want to give them your email, 10minutemail works nicely. They also ask for some other details, but none of them are checked, so you can just put whatever there.