Plex: A required codec could not be found or failed to install

Plex: A required codec could not be found or failed to install

While it’s slightly off-topic for a security blog, I recently spent some time troubleshooting this issue and hope this may be of use to someone!

I recently set up a new media server, this time running TrueNAS Scale - Overall I’m impressed, but I had one nagging issue after setting up Plex via the TrueNAS applications menu - After trying to play some content, I received the error:

Playback Error - Conversion Failed. A required codec could not be found or failed to install.

Troubleshooting this took a while as this appears to have been an issue for various reasons over the last few versions - as of October 2023 the underlying issue seems to be with the naming of the EasyAudioEncoder within the codecs file itself. Specifically, by default it’s suffixed with .tmp, and it shouldn’t be.

The steps to resolve the issue are therefore:

1. Identify your Config folder location - if you don’t remember this, click on the “three dot” menu next to your running container in the TrueNas Applications section, it’s one of the options you defined when you installed Plex.
2. Go to System Settings - then “Shell” in the TrueNas Menu.
3. In the shell which opens up, use the command cd "<config folder location>/Library/Application Support/Plex Media Server/Codecs"
4. Use ls -lah to list the contents of the folder, and you should see that your EasyAudioEncoder version has a .tmp extension The exact file name will vary based on the version, mine was EasyAudioEncoder-1978-linux-x86_64.tmp
5. Simply use the command mv EasyAudioEncoder-1978-linux-x86_64.tmp EasyAudioEncoder-1978-linux-x86_64 to remove the unneeded .tmp extension
6. Run ls again to verify that the .tmp is now gone.

That’s it! You fixed the issue!

Here’s a quick example:

root@Zeus[...tion Support/Plex Media Server/Codecs]# ls -lah
total 108K
drwxrwx---  4 1000 1000  5 Oct 29 08:18 .
drwxrwx--- 13 1000 1000 17 Oct 28 12:25 ..
-rwxrwx---  1 1000 1000 36 Oct 28 11:04 .device-id
drwxrwx---  3 1000 1000  3 Oct 29 08:18 EasyAudioEncoder-1978-linux-x86_64.tmp
drwxrwx---  2 1000 1000 13 Oct 28 18:09 a31c019-4614-linux-x86_64
root@Zeus[...tion Support/Plex Media Server/Codecs]# 
root@Zeus[...tion Support/Plex Media Server/Codecs]# mv EasyAudioEncoder-1978-linux-x86_64.tmp EasyAudioEncoder-1978-linux-x86_64     
root@Zeus[...tion Support/Plex Media Server/Codecs]# ls
EasyAudioEncoder-1978-linux-x86_64  a31c019-4614-linux-x86_64
root@Zeus[...tion Support/Plex Media Server/Codecs]#