I plugged the USBs of my GameCube controller adapter in, and chose "GameCube Adapter for Wii U" under Port 1, but it says "No Adapter Detected." Could someone please help me to get it working?
I used this 3rd party adapter:
https://www.ebay.com/itm/193817336722
I used this 3rd party adapter:
https://www.ebay.com/itm/193817336722