Newb Linux Ubuntu getting Conversion failed. The transcoder failed to start up

Plex Media Server
1

Server Version# 1.43.0.10467
Player Version#: 4.156.0
<If providing server logs please do NOT turn on verbose logging, only debug logging should be enabled>Version

Hi,

Semi newb with Ubuntu 25.10

had to switch win 10 :frowning:

$900+ cpu not win 11 compatible

lol

but was working fine

now i get Conversion failed. The transcoder failed to start up.

Im guessing driver issue?

but have 580.126.09 installed running 2080 TI

Threadripper 1950X

I am at a loss, any help appreciated

2

Can you please provide the server DEBUG logs ZIP file which captures the attemp at playing?

3

Plex Media Server Logs_2026-02-05_10-06-26.zip (247.2 KB)

4

There is a major configuration issue with the network adapter.

Feb 05, 2026 09:14:21.207 [135483898763920] ERROR - Error creating directory "/home/plex/Transcoder": Permission denied
Feb 05, 2026 09:14:21.215 [135483518466872] ERROR - NetworkService: Couldn't join multicast group: set_option: No such device [system:19 at /home/runner/_work/plex-media-server/plex-media-server/build/dependencies/plex-media-server/standard-x86_64-linux-musl/boost/include/boost/asio/detail/reactive_socket_service.hpp:174:33 in function 'set_option']
Feb 05, 2026 09:14:21.215 [135483518466872] ERROR - Error broadcasting message: send_to: Network unreachable [system:101 at /home/runner/_work/plex-media-server/plex-media-server/build/dependencies/plex-media-server/standard-x86_64-linux-musl/boost/include/boost/asio/detail/reactive_socket_service.hpp:261:33 in function 'send_to']
Feb 05, 2026 09:14:21.215 [135483518466872] ERROR - NetworkService: Couldn't join multicast group: set_option: No such device [system:19 at /home/runner/_work/plex-media-server/plex-media-server/build/dependencies/plex-media-server/standard-x86_64-linux-musl/boost/include/boost/asio/detail/reactive_socket_service.hpp:174:33 in function 'set_option']
Feb 05, 2026 09:14:21.215 [135483518466872] ERROR - Error broadcasting message: send_to: Network unreachable [system:101 at /home/runner/_work/plex-media-server/plex-media-server/build/dependencies/plex-media-server/standard-x86_64-linux-musl/boost/include/boost/asio/detail/reactive_socket_service.hpp:261:33 in function 'send_to']
Feb 05, 2026 09:14:21.215 [135483518466872] ERROR - NetworkService: Couldn't join multicast group: set_option: No such device [system:19 at /home/runner/_work/plex-media-server/plex-media-server/build/dependencies/plex-media-server/standard-x86_64-linux-musl/boost/include/boost/asio/detail/reactive_socket_service.hpp:174:33 in function 'set_option']
Feb 05, 2026 09:14:21.215 [135483518466872] ERROR - NetworkService: Couldn't join multicast group: set_option: No such device [system:19 at /home/runner/_work/plex-media-server/plex-media-server/build/dependencies/plex-media-server/standard-x86_64-linux-musl/boost/include/boost/asio/detail/reactive_socket_service.hpp:174:33 in function 'set_option']
Feb 05, 2026 09:14:21.215 [135483518466872] ERROR - NetworkService: Couldn't join multicast group: set_option: No such device [system:19 at /home/runner/_work/plex-media-server/plex-media-server/build/dependencies/plex-media-server/standard-x86_64-linux-musl/boost/include/boost/asio/detail/reactive_socket_service.hpp:174:33 in function 'set_option']
5

fixed

reinstalled ubuntu

had swapped gpu and network

working now

Correction

Some work some dont

huge library please help

cant upload logs 8.6mb max is 8

6

Update

think this might be a codec issue?

files play VLC Ubuntu

but not native says missing Dolby TrueHD decoder & H.265 (Main 10 Profile) decoder

7

Upload a new set of server logs that capture the problem.

  1. Stop Plex, wait 10 seconds, start Plex
  2. Wait 2 minutes for Plex to log the startup sequence
  3. Recreate the problem
  4. Pull & post the server logs

The zip file should be small enough to upload. If not, upload Plex Media Server.log and its rollovers, Plex Media Server.1.log through Plex Media Server.5.log.