I was playing as the Terran Alliance and was doing quite well, having the largest civilization. It was down to 4 civilizations - Terran Alliance, Altarian Resistance, Mowlings, and the Yor. It was turn 339. I had an alliance with the Altarian Resistance to turn 376. The Altarian Resistance also had an alliance with the Mowling. I was at war with the Mowling and the Yor. The Yor was at war with all the other civilizations. On turn 339 the Yor suddenly terminated and the game ended stating that I was defeated due to a Galactic Alliance without any further explaination. Not sure why the game would not continue at least until my war with the Mowling had ended, at which time I hoped to still be in an alliance with the Altarian Resistance?