Unreal launcher crashes on start on Mac

Booting up Unreal Launcher on Mac crashes. It goes through ‘verifying’ and then crashes shortly after, reboots, and crashes again. What’s going on/how can I fix it?

16 GB RAM, 2.2GHZ intel i7 quad core
OS X 10.11.6

Epic Staff will tell you that AnswerHub is for Unreal Engine, specifically, and that for Launcher issues you should go to http://help.epicgames.com/ where you can find information and solutions for common issues, as well as a contact form if you still need additional assistance. Another thing you can try is troubleshooting this yourself by checking out A new, community-hosted Unreal Engine Wiki - Announcements - Epic Developer Community Forums.

On a side note, I have personally found Epic Games products to run better on macOS Sierra starting about November 2016. Consider upgrading if that is an option for you.