Cannot start server after upgrade: FFmpeg validation: The process returned no result

[mwl]

This is Server Core, there is no Start Menu or Control Panel.  I repeat: there is no ffmpeg.exe in any of the folders in PATH.  It's not finding an alternative ffmpeg, because there isn't one there to be found.  Nothing in PATH references ffmpeg.  There is no stray FFmpeg installation on this box, it's a VM with the OS image and Jellyfin installed on it.

As the binaries are in Program Files and the server is being started with a data path of ProgramData, would encoding.xml need to have an explicit path to the location of ffmpeg.exe in order to find it?  I would expect not, because I don't recall having to set it for previous versions.