Incorrect username: Use Battle.net id?

[Xyzt]

So i'm currently having this error or issue.

 

I was playing this same morning, leveling up and stuff etc. doesnt matter. And the power went off, so i was like mehh. Lets go to school instead. But now that i came home I got this??

 

http://i57.tinypic.com/1zyzrpc.png

 

So i'm unable to log in?

 

Help please

[SeCkadiin]

Follow all steps from this thread (Make sure that you have downloaded the English config).