What happens when your Macbook says it can not connect to your Apple TV.

You have the best plans for this next class, you are going to have them use Kahoot to go over the latest English terms...uno problemo...your MacBook keeps telling you that it can not connect to your Apple TV.  You have checked your connections, you are on the same network and all that fun stuff still nothing.  You call IT.  They can connect with their iPhone and your iPad, so what gives???  It seems as though your Apple TV has updated itself to its latest software rendering unrecognizable by the MacBook because it is running an older iOS.  We updated the MacBook to Sierra, NOT High Sierra, and everything started working again.  If you have downloaded Sierra before, and do not want to update to High Sierra just yet, log-in to the App Store, click the "Purchased" tab and scroll down to find Sierra, download and install. Depending where you are it could take a while, but after the install your MacBook and Apple TV play nice again.