window will not maximize

Do you have any CC? Try taking that out.

Is your game up to date? It happened to me, but when I updated my game, it stopped. If your game isn't updated, try updating it asap & see if that works.

@shimmeritpink you could also try this: http://sims4.crinrict.com/en/2014/09/deactivate-origin-in-game/