I know this is an old thread but i believe this is what the OP was looking for.
https://mkey.salthax.org/
Did you enter the wii u and correct inquiry number from wii u?contacted nintendo and they want me to send them the console to wipe it....says nothing about that on the gamepad screen, i give them enquiry number and they are supposed to provide a master key correct?
anyone know why the key generator isn't working for me?