So I just updated KSP to 1.3.1 (after about 3 years of not updating!) I'm currently on OSX Yosemite 10.10.5.
The issue I'm having is the game gets to the "Loading Asset Bundle Definitions" point and then stops loading.
I downloaded the update and the KSP_osx folder is in the Applications folder. I have tried moving the KSP and Launcher apps to the desktop and back again, that hasn't worked. I also tried the method of right clicking and going through "Show Package Contents" to open the exe.
I would upload the log, but can't seem to find that either!
Any help would be much appreciated.