Error - Android Emulator of standard Ionic Conference app

As a set to see if my Android Studio is working on my Mac (OSX), I’ve used the standard Ionic Conference App. I’ve installed it with the CLI command and then successfully build it. When I can it on a Nexus 5/6 emulator, I’ve got this error within the emulator. Any ideas what this might be? Many thanks!

Application Error

The connection to the server was unseccessful. 
(file:///android_asset/www/index.html)