Shield says I have a hack?

Okay. I haven't played this game in ages and decided wtf, ill make a new account. I reinstalled this game and whilst doing the beginning tutorial I get a pop up that says it detected a hack and the game just closed. I try and long back in and it says im banned for 0 days 1 minutes ect. Why is this?

EDIT: it says i had a wrong game client. I literally just installed the game and got the download for the client off of the website.