You cannot define a new game because your null level does not allow you to play more than 5 games at once and you are already playing (including your game invitations) 5 games.
You can solve this unpleasant situation by upgrading your membership.
(hide) If you want to save on bandwidth you can reduce the amount of information that shows up in your pages in the Settings. Try changing the number of games in the main page and the number of messages per page. (pauloaguia) (show all tips)