Using the Plex App on a 2019 Nvidia Shield, with my Plex Server hosted on Windows 10. I recently turned on cinema trailers for movies. When I play a movie, and a trailer plays for a movie in my library, everything works fine as expected. However, when a trailer for a movie in theaters plays, there is no audio. Has anyone seen this that can lend a hand?
Some details are that I do not have any trailers downloaded onto my server directly, so nothing regarding these trailers is pointing to a file I have somewhere on my server. I already tried disabling passthrough, as well as switching the pass-through to optical from and disabling all codecs in the settings that appear when optical is enabled. Same issue in all cases. I also noticed that when a trailer for a movie in my library plays, the audio for the player shows as “AAC Stereo”, however, when the trailers for movies in theaters play, it says “AAC External Stereo”. I am sure this is related, but I am new to this, especially audio and transcoding. What I could find online said to disable pass-through but as I mentioned, I already tried that. Any help would be appreciated!!
I can reproduce a closely related Cinema Trailer issue across multiple Plex clients and have captured a specific PMS-side failure.
Server: Plex Media Server 1.43.5.11079-b3b13e506 on Windows.
Android: Pixel 9a, Android 17, Plex 2026.20.0. Online IVA Cinema Trailer video Direct Plays but audio is silent. PMS reports a selected AAC stereo track, yet three requests to /library/streams/1598532 (the audio-stream ID) return HTTP 404. Reducing quality to 720p did not fix it; playback remained Direct Play.
Roku: Streaming Stick Plus 3830X, Roku OS 16.0.4.853, Plex 9.21.12.12191. Instead of silent playback, the trailer stops with “Conversion Failed. The transcoder failed to start up.” The PMS log shows:
GET /library/streams/1598705?autoAdjustSubtitle=1
404 GET /library/streams/1598705?autoAdjustSubtitle=1
Error configuring transcoder: TPU: Failed to download sub-stream to temporary file
In the Roku case, 1598705 is the video stream ID. PMS selected HLS/MPEG-TS with video and AAC audio copied, then aborted on the internal 404.
I independently downloaded and tested an IVA trailer: H.264 video, AAC stereo audio, audible in VLC. Locally hosted movies play audio normally. This points toward Plex’s handling of external trailer stream references rather than an inherently silent trailer source. I cannot yet prove that the Roku and Android symptoms have exactly the same root cause.
