Why can't I start Halo 3?

So I've created a new Xbox live account and because I bought it digital it was on my main account on it and when I start the game comes this error message "Halo 3 can't start" can someone help me?

Download Halo 3 from your main account and try again with your new one. - As a precaution, make sure that you have the console as the main console for both accounts.