I just downloaded the newest version of KSP (1.1.3) and the Launcher will not let me press "play" or update my settings. Along with this when I open the game directly it freezes and the screen says "Loading Asset Bundle Definitions." I left it for a night and it never launched. I've been playing this game since 2013 so this is disappointing.
MacBook Pro (Retina, 13-Inch, Early 2015)
Processor: 3.1 GHz Intel Core i7
Memory: 16GB 1867MHz DDR3
Graphics: Intel Iris Graphics 6100 1536 MB
Software: MacOS Sierra (10.12)
This computer is more than capable of running this game, I have tried: re-installing multiple times, downloading older versions, using the installer, using the direct .zip version, I have installed new and old Unity Players (5.2.4/5.4.1) and still nothing works.