Crash after launch on Mac with USB device connected

Yes, same machine Mac Pro with 680 GTX Mac Edition. I’m on 10.9.2 up to date. Windows partition is on same Mac via Bootcamp.

Always same. I start Unreal Launcher just fine then I try launch button for Editor 4.0.1, then splash screen, then a glimpse of editor’s wizard, then crash (without any message).
Always same.