It looks like you have other processes running in parallel with the game that can put a heavy load on your RAM and / or CPU. Perhaps that's why your computer just doesn't have enough resources to handle this. Of course, I could be wrong, but this is the most logical thing possible.
Nah, thats not going to be it. As I said, I've been playing on En Masses client just fine for ages. Switch publishers, switch clients, now I crash. Gonna see if a re-install fixes. Somethings corrupted.