The Arduino Sketch does not save in Arduino folder location
Download the latest IDE from Arduino.cc
Drag your Arduino application icon to the trash.
Open up terminal and type rm -r ~/Library/Arduino15
Delete the Arduino folder in your Documents folder for good measure
Drag the newly downloaded Arduino application to your application folder and see how it goes from a clean install.


Failing that PlatformIO IMO is a much better IDE for developing on these platforms : http://platformio.org/