What browser are you using? It sounds like you have something activated your browser that won't let you access the CC tournament page. A couple of things to try.
First the most obvious thing is try a different browser.
Second type http://www.wgt.com/gameclient.aspx directly into your browser address bar. That will take you directly to the game client page and try to go to your CC tournaments that way.
Third look at all your browser settings to see if you have a setting resembling the message you are getting activated and if so deactivate it.