I have been playing the current beta. At times, during the computer's turn, I hear the sound of an explosion, as from a ship combat, but the fight takes place off screen. When that occurs, the "turn" button does not come back on. I can move around the screen and access the menus, but I can not give any orders. The only way out is to save the game and exit the program. When I restart, I load the savegame and the "turn" button is back and I can play from that point.