I can't really imagine what the root of the problem is. I had literally no issues at all from beginning to end, save for the download time. In fact, I was actually impressed with how smooth the setup was and thought someone who wasn't savvy could do this no problem. Then it's like the polar opposite from others. It won't even connect to their Wi-Fi, constant hard locks, gamepad disconnects...
What the hell is going on inside this system? Maybe it's a hardware thing, I have no clue. I just hope it's something an update can actually fix for those having the issues :-(
i honestly think that the issue is because the wii u probably has some troubles with some routers... the irony is that mine is made by cisco.
anyhow the update actually solves the wi-fi issues, the problem is that to install the update you have to connect to the internet your wii u <.<