Can't open Mac version

My friend was going to join CC but was met with a file type he cant open on mac so he cant play it.

I believe hes on Mojave.

UnknownShadow200 🔧 Tue May 14 at 14:03:08

Was this message when attempting to extract the .tar.gz or when attempting to run the game?

Did he download 1.0.3 beta or an earlier version? (earlier versions were called classicube.osx and had that problem)

What is the exact message he sees?