I am having the same issue with the code error 199-9999
I got my wii u from amazon.com yesturday via FedEx 1 day shipping
Right out of the box I hooked everything up
HDMI,Power block,senc Bar, gamepad charging.(nothing else hooked up to it)
my router is actually about 8 feet away from it so that cant be the issue also i have the game pad about 1 foot away from the system.
Note-I have nothing plugged into the system no sdcards or usb items.
I did the basic setup - set up time/date/Tv Remote/wifi/network id account info, tranfered my mii from my 3ds XL with no issue
it said i needed to update so i download the update took about 30-40 min then it installed
after first reboot it told me I had to install gamepad update hit "ok"
seems to start the update then almost as if the gamepad restarts byitself cause the screen goes black as if it powers down showing me the nintendo start screen logo and it tells me "error code 199-9999 wouy system will restart.
it does this every time. its now next morning and still same issue.
I will call nintendo as soon as they open and update with what they tell me.