I just bought Codea on the App store and tried to activate Air Code. It displays an error message sayin that an error occured while createing the server (in german). The iPad is connected to a Wifi network.
Anything I am missing? A setting?
I does not work on an older iPad, model A1430 (full size with retina display)
I think this is a bug: The iPad have cellular as well. When reboot the iPad, use WiFi, I can connect. The I turn of WiFi, cellular connect. Air Code works, with the cellular IP. Then I turn on WiFi again, AirCode no longer worked. It seeme Codea is not in love with WiFi+cellular 
@mbalmer thank you for finding this! I’ll have to try to replicate this.