I am running the game through Steam on a Mac (10.11.6) and have done for quite a while.  However, for some reason, the game refuses to run properly now.  All I get are the Amplitude, Iceberg and Endless Space images, but then the game shuts down.  I have tried verifying the game's files (numerous times), switched off the In-Game Steam Overlay and done everything I can to get this game to work.  Is it a software issue?