I actually found the inspiration on https://github.com/MichaIng/DietPi/issues/2916.
I think it is new in Debian Buster that the user needs to be added to the “render” group.
I think also this needs to be fixed by Plex itself when installing Plex on Debian Buster with “apt-get install plexmediaserver”. It creates the plex-user, but does not add it to the correct group.
You need sudo to run that command, but it just adds plex to the group render.
Afterwards I rebooted the box, but I think a restart of plex itself should be OK.
My box is that (in)famous AtomicPi, but IMHO it’s a decent plexbox, certainly now with HW-transcoding.
