Can't launch game in 18 or 18.1 on mac running os 10.11.6

Tried to open 18 & 18.1 on my mac through the launcher and both times i received the attached error and then the launcher froze and i wasn't able to quit the launcher and was forced to restart my laptop. Since then anytime i try to start 18 or 18.1 it starts "preparing" then halfway through it automatically quits with no error message. So i am unable to play the latest versions. A fix would be greatly appreciated.