When either I or my brother tried to change our account info, we were greeted with the error code above. To recreate the issue, one of us click our profile icon on the top-left of the home screen with the apps. Then we clicked on “Change Account Info” and we typed our passwords repeatedly and correctly without success. Thanks for any help!
Changing account info might not be supported on Wii U, I know the support for it is limited, can’t change anything from the website but I was able to change settings from my 3DS