Yeah, I know there have been a lot of issues with the Mac client- I took a break for a few months, decided to pop back in and found it completely broken for about a month.
I had an issue where the installed launcher would just freeze and never launch the client. What finally fixed it for me was installing Xquartz:
But in regard to the OP, I’m not sure that the OS version is causing the issue on the installation, but even if that wasn’t it, the game is no longer supported on that build.