Downloaded Enigma version 1.21, copied the app from the dmg to Applications. Opening either from Applications or directly from the dmg, I get a couple of verification questions the first time I open it, and then it quits. After that first time it quits immediately upon opening.
OS X El Capitan version 10.11.5 on a mid 2010 Mac Mini, 16 GB of RAM.
Martin B. Brilliant at home in Holmdel, NJ