This might be an obvious question, but did you enter the correct "WiiU Title Keys" website in WiiU USB Helper Settings?
It seems that all the errors you are getting is related to the Title Key website.
We cannot give you a link to the Title Key website, due to copyright laws.
HINT: But you can Google "WiiU Title Keys".
Yes I did enter in the correct Title Key website. I purposely covered it on as the OP did not want it shown in his post.