My Endless Legend installed through Steam, everything is updated.

I also followed trouble shoot and installed Mono Framework, and verifying the integrity for steam cache.

Finally I found that the game would crash when I have 2 monitor, once I removed the extension monitor the game can start normally.

Here is more about my environment:

Macbook Pro 15" 8GB ram with Intel i7

macOS Sierra 10.12.1

Have the same issue. i7 2015 16gb ram  el capitan

I managed to run it with the monitors unplugged in windowed mode and then plug them back in and it still ran but i dunno how long it will play for.

Have been having the same issue. 

Decided to run the game in 32-bit through Steam>Endless Legend>Properties>Betas> Change the drop down menu option to 32-bit. 

This ended up fixing the monitor issue...BUT... I now have no sound. When I click on the options from the main menu, the audio tab is overlaid with ERROR: Failed to initialise the sound system! in bright red writing.

Still can't figure this out. 

Please help Dev Team!!

Me too. I'm glad I found this because it would never in a million years occur to me that unplugging a monitor would make a game not crash.