Fix: The Transcoder Crashed or Failed to Start Up

There are many errors that can appear when Plex Media Server attempts to transcode a media file. Most transcoding errors that are displayed don't provide much information as to the cause of the error, so it is up to the server owner to try and resolve the issue.

An example of one such Plex playback error message is:

Conversion failed. The transcoder crashed or failed to start up.

If you get this message when streaming a movie that is being transcoded, then there are a few things that you can try to resolve the issue.

Check the location and permissions of the transcoder temp directory

Verify that the location of the temporary transcoder directory is in a directory that the user running the Plex server has write access. Plex writes out blocks of the media file as it transcodes so it can stream the file to the client machine, and these blocks are written to files in a temporary directory.

If Plex can't write to the directory, then this could cause this error. Ensure the directory is accessible and writeable by the user running Plex.

Delete the transcoder directory

If you have verified that the permissions to the temp directory are fine, but you still get the error, try deleting the transcoder temp directory. The directory will be re-created the next time Plex transcodes a media file.

Disable hardware acceleration

Some times a bad driver can cause the transcoder to crash, and result in a transcoder error. Try disabling hardware acceleration to see if the error is resolved. If it does resolve the error, try updating or reinstalling the graphics card driver, and then re-enabling hardware acceleration.

Change audio setting

The audio selection for the media file could cause the transcoder issue. Try setting the audio to stereo to see if that resolves the problem.

Windows users: check key or keyset

For Windows users, if you check the Plex logs on the server you may see messages that say the following:

Key not valid for use in specified state


Keyset as registered is invalid

The above messages indicate an invalid key or keyset, and Plex recommends trying the following:

  1. Stop and exit Plex Media Server so it isn't running.
  2. From Windows Explorer, delete the following folder:
  3. Restart the machine.
  4. Start the Plex Media Server.

Do the Plex dance

The Plex dance is known to resolve several issues with Plex, and can be tried if many options fail. This is one of those last-resort type of options as it does involve several steps that can take a while if you have a large library.

The following steps outline how to perform the Plex dance.

  1. Move all the files for the media causing the issue out of the media folder being used for the Plex library.
  2. Scan the library to detect the changes.
  3. Empty the trash and clean the bundles to ensure the media item has been cleaned from Plex.
  4. Verify the naming convention (TV show naming/movie naming) for the media files, and then move them back into the folder.
  5. Rescan the library a second time, and ensure the media item has returned to the library.

If the above three solutions didn't fix the codec issue, then the next step would be to try asking for solutions on the Plex forums.