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) In the mood for a quick game that is guaranteed to finish within 2 hours? Create a new game of your preference, select the Time for game and set Time to 0 days / 1 hour, Bonus to 0 days / 0 hours and Limit to 0 days / 1 hours. (TeamBundy) (show all tips)