If you have some mobs/minions around you and try to place a spirit flag it doesn't place I have tried up to 5 times to get it placed.  I think it has something to due with collisions of flag with mobs or minions I am not sure though. But sometimes after trying to place the flag a few times game just closes to desktop. Eventually it will place or game will close to desktop. I have only seen the crash 2 times after playing about 3 hrs. I played the queen of throns for over 8hrs an not a single crash.