Case 1

Network selection worked, firmware update message came, then error.

Solution: Worked on a different WiFi network.

Messages:

Choose a network

Connecting to network...

and

Network Status

Successfully connected!

and

Checking for software update...

and

Unable to connect

Please check your internet conection and try again.

Case 2

Error already when selecting WiFi network.

Messages:

It seems we're unable to connect to the OUYA servers at the moment. We'd recommend confirming your Ethernet and Wi-Fi settings before trying again.

and

Cannot establish a connection with the OUYA Servers. To turn on Wi-Fi, unplug your Ethernet cable and proceed. To retry ethernet, please check your connection and then unplug and re-plug your cable.