With a 360 controller plugged into my MacBook Pro, pressing DPad right while playing in editor will crash editor. This occurs in any project, including Tappy Bird and Content Examples.
Looks like you’re having same USB device bug others are experiencing, but it isn’t triggered until d-pad is hit. Try this patch: http://cdn.unrealengine.com/qfe/QFE-FromCL-2027741-Shelve-2030404. I reproduced your issue and after installing patch, d-pad does not trigger a crash for me. Let me know if that doesn’t fix it for you!
Please note that patch is just a quick fix so you don’t have to wait for 4.0.2 release. It will be removed if you try Verify Install from Launcher (in which case you’ll just need to install patch again).
I’m trying this patch with my Mac Pro 2013 and it’s just rotating display diagonally. I didn’t get crash before with 4.0.1 but it same behaviour I saw before patch.