Do you only get the error when you have subtitles enabled? If yes, then this could be two different bugs.
If you get the error after the last subtitle line (usually at the end of files, but in your case it could be earlier) then it’s the bug “(Transcoder) Unexpected behavior when subtitles ended before the end of video (#14426)” which is fixed in server version 1.32.6.7468.
But if you get the error after seeking/jumping in the file then it’s the bug that I reported here: LG C9 TV: Conversion failed. The transcoder exited due to an error happening occasionally - #68 by cremor
If that is the case, then please post there with details of your setup.
