If not done already, lower projector screen by hitting Apple icon on the Extron MLC / Black Box Controller)
Enable Bluetooth
Click the Airplay Icon in the top right of the toolbar
Enter the 4-digit AirPlay code displayed on the Projector Screen
In Chrome, open up chrome://settings/. (⌘ + , or Chrome > Settings)
Turn off Hardware Acceleration when avaiable under the Settings > System Menu
Restart Chrome
Connect to Apple TV