...completed LR...entered the Lucky 38...in the presidential suite...a shootout between Cass and ED-E...not sure who fired first...couldn't interact with either while they fought...Cass died...everytime...could loot her body then...could never talk to ED-E...ever.

I don't understand it. I tried to reload an earlier save but it kept happening. I've verified game files and defragged but nothing has changed. As soon as I enter the presidential suite Cass and ED-E go at it. None of the other companions react except to make comments such as "Not my fight".