I can no longer access the Trailhead playground to complete the challenges. It has been working for the past week and randomly stopped. Attached is the picture of the landing page I arrive on when clicking the "Launch you hands-on org" link. I have logged out and logged back in multiple times with no success. 

Any feedback will be greatly appreciated. 

I can no longer access the Trailhead playground to complete the challenges. It has been working for the past week and randomly stopped. Attached is the picture of the landing page I arrive on when clicking the "Launch you hands-on org" link. I have logged out and logged back in multiple times with no success. 

Any feedback will be greatly appreciated. 

 Keeps showing Challenge Not yet complete... here's what's wrong:  The "Open Activities" related list does not appear to the first one on the Account record details page. It does and I have gone as far as removing all other lists. What do I do?