Just a note for anyone that goes looking.
I'm running Emby Server on a headless MacMini that I've recently upgraded to macOS 10.15 Catalina. After remotely installing the beta Server, I could no longer get Kodi or Emby Apps to play media.
Being headless, I didn't see that the OS was asking to give Emby permissions to access the respective Volumes and folders it requires, and the operating system was blocking access.
So, before anyone else pulls their hair out encountering this, if you upgrade Emby server on macOS Catalina, after starting it up be sure to look out for the folder access dialogs and give Emby the access it requires.
Also, on Catalina, after updating/installing Emby Server, you will need to right click and select "open" on the app. The OS will tell you it can't open it due to security reasons. Select cancel, then right click and select "open" again. This time you will be allowed to open the Emby Server app and all will be right with the world again.