OK, had a major bug with MoI and OSX Mavericks.

I was screen sharing with Skype to show a friend about MoI just now. Used my older 27" iMac as a screen to my Macbook Pro Retina.

First I used the latest "MoI v3 beta Aug-1-2013" and everything froze. My computer logged out and when I logged back in again, the beta was not possible to open again.

Then I used the "MoI v2.52" version. And my whole computer froze again, but I was still able to speak to my friend over Skype.
Forced to restart the computer.

UPDATE: Seems to be something with Skype. Tried opening it with same setup, but without Skype running screen share. Works fine. Could open the Beta again too.

Hi Fake Pilot, typically that kind of "whole machine" freeze is related to something going wrong at a driver level. Hopefully Apple will fix what's probably a graphics driver problem there in an update.

If you do a google search for "skype mavericks freeze" it looks like many others have similar problems with Skype on Mavericks currently.

- Michael