SOLVED: "Playback failed due to a fatal player error." (Only in Firefox)

[DeNewGuy]

Replace this

Code:

    devices:
      - /dev/dri:/dev/dri

with this

Code:

    devices:
      - /dev/dri/renderD129:/dev/dri/renderD129

Right now you are passing in both the Arc GPU and the iGPU in your CPU.  Jellyfin does not currently have a way (yet) to tell QSV which GPU to use so it uses the first available GPU, renderD128.  Which is going to be your iGPU.

Thank you for your quick response.
When I try this I get an error message saying; there is no such file or directory.
When using the ls command in the dri folder I'm getting the following back:
by-path  card0  renderD128

Would the card0 be the dGPU then?