The newest update to macOS, Catalina, introduces a number of new requirements for applications. It's taken a little while, but I've now released an update for Airships that should be compatible with Catalina.
If you encounter any issues, please do get in touch.
Addendum: Steam mods should work once again now. Also, if you want to read a long blog post about the Catalina stuff and how to make your own game run on Macs now, here you go.