I have recently deployed a Windows Server 2019 Core server (one of three.)
I am having trouble installing the App Compatibility FOD - it comes up installation successful, but when I reboot I get messages about 'installing updates' and 'update installation failed, rolling back changes'. When the server boots back up, the FOD is not installed.
Verify what is your Windows Server version, current is 1909. First, update your version and than download the FoD from the Microsoft Volume Licensing Portal and try install again, as the Microsoft guide: