After playing a game for a while, no matter how many units are on the screen at one time...EVENTUALLY the visual effects will vanish, aka guns will fire, will hear the sound, the enemy will take damage but the shot itself will be invisible, also when ships explode the explosion will be invisible..the ship will just disappear.
If I save the game at that point and load it again...it will return to normal only to vanish again after I'd say 20-30 minutes into the game.
Any suggestions on how to fix this?