When you attempt to enroll a Wi-Fi device and the process fails with an Unknown Error or Discover Failure, please check the following:
When you get the failure message, what is the color and state on the LED?
If the LED is solid green (or turns completely off if the light it is controlling is on), close the enrollment process by pressing the X at the top-right and then select Yes, Exit Setup
Do you see the name of your Residence listed at the top of the app?
At the top of the app your Residence name should appear in the middle. If you only see a drop down area and no text, press to the left of the arrow:
Choose your Residence from the drop down list:
Attempt to enroll the device again after following all of these steps to see if you are successful.