He bro, was having the same issue. So this is what worked for me just now.
Go into your WiiU forder>environments>tiramisu (or whatever you are using) >modules and get 'nimble.rpx' out of that folder. Just toss it to the main directory if anything so that you don't lose it in the future. Moving Nimble makes it sign into your NNID.
I hope this info is helpful