LEGO Mindstorms EV3 crashes on OS X El Capitan
Check if you have Silverlight plugin on your mac:


Access your hard drive
Double-click the hard drive icon on your desktop
Find the plugin
Navigate to your Internet Plug-Ins directory: /Library/Internet Plug-Ins/


If installed: 


Remove the plugin
Drag any of the following into your trash bin:


Silverlight.plugin



Then dowload and install the Silverlight plugin from here:

https://www.microsoft.com/silverlight/

If not ok remove and reinstall Mindstorms software.