From MacOS Catalina user

[MichaelZ38]

Hello The Indie Stone. I am a Russian user of your game in steam. You made a very cool project. I write to say that I am very upset that I can't play Project Zomboid on MacOS Catalina. Could you upgrade your game to Mac OS Catalina? If Yes, when will you do it?

[OffitMan]

I had the same issue as I foolishly upgraded to Catalina without considering that Apple have removed 32bit app support.

 

To get around this, I created a partition on my Macbook and installed Mojave. There are plenty of guides on how to do it but if you do decide to go down that road and have issues, hit me up on here and I'll help if I can.

[EnigmaGrey]

You ignore the message and press start.

 

source: I use Catalina.