Smash for Wii U has potentietly has a system breaking bug!!!*Update* seems to be a factory error with your Wii U system and not caused by Smash.

[episteme]

Damn, my 2 year warranty expired 2 days ago...

But I have the digital version on an external drive.


If that error occurs to you: don't format the system memory!

 

EDIT: the error isn't Smash specific, it's a save game error that can happen with other games, too.