Our organization uses Chatter as our internal group chat feature. We noticed that the "chat" feature (where we chat one or more person privately) - is gone. We still have the "message" feature, but the "chat" feature was preferred as those messages aren't tracked. Can you tell me what happened?

For the Create and enable compact layout challenge, I'm receiving the following error message:

Challenge Not yet complete... here's what's wrong: 
Could not find a compact layout for the Event object with the label 'Showing Mobile Layout'.

Here's the Showing Mobile Layout compact layout that I created:



What am I doing wrong? Thanks.