Hi all this not a bug but, it did cause my game to crash a dozen times before i figured out what I was doing wrong. I had declared war on an empire but, I could not invade their systems. It turns out I had to declare war on the minor faction the parent civ had acquired the system from. what kept crashing my game was trying to attack a hero without any ships with it. The other snag was I couldn't declare war on this minor faction until I discovered a world they still controlled.

Overall I love the game and each update makes me more confident that the final release and dlc's will make this game better than the first. Just thought I would share.