Network

Network
That might happen because the WiFi software in the console "crashed", or because the WiFi in the console is defective.

Try to restart your console by holding the power button for at least 10 seconds.

Then turn the console on, and see if the console now sees your wireless network.

If not, try to
factory reset the Xbox console.

If that also didn't help, sign up your console for repair at
https://devicesupport.microsoft.com

:)