When ARES Commander 2019 crashes at the start then it could be an issue with a blacklisted OpenGL-Display driver. In this case please open an Apple Terminal command window and start the application once with the following parameters "-glprofile compatible. 

Below the complete command line to paste into the Terminal:
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​/Applications/ARES\ Commander\ 2019.app/Contents/MacOS/ARES\ Commander\ 2019 -glprofile compatible