Hey I was having the same issue and while surfing the net for a solution I found this. It help me so maybe it'll help you too.
Re: Error 111-9000: eShop refuses to load
So I figured out what the problem was with the Error 111-9000 code. What actually was the problem was the power to the Wii U. I recently bought an extra power supply unit. (those things with extra outlets) and when i had the wii u plugged into it..I noticed my Netflix wasn't working and the Eshop wasn't working either. Thus getting the error code message. So I tried messing with the internet and nothing seemed to work. So I took out the extra power supply unit and plugged the Wii U directly into the home outlet and everything was perfect again. And just to check that it wasn't some freak lucky fix I tried it again with the extra power supply unit and sure enough it wouldn't work. So if you have your Wii U plugged into some extra outlet remove it and try a home outlet. If that doesn't work then you're not getting enough power to your console
Hope this helped.
I also may post a video on youtube on how to fix it because there is literally no information anywhere on how to actually fix this problem.
Also If you have an external hard drive that doesn't have its own power supply it may also be sapping energy from the Wii U and causing this Error.
Please let me know if this works for you as well