Unreal 4.20.3 Wont launch from Epic Games Launcher

Hey, I’m running OSX 10.12.6 (Sierra) All troubleshooting from launcher says everything is fine and is above recommended specs etc. 4.20.3 is installed but when I click launch it goes “please wait” goes blank for a second and then reopens launcher as if I haven’t done anything… Any Advice (I just want to compile a Mac version of a game built on pc for testing)