It was fine when the first episode came on, and then this happened.
Remote Windows client, server on NAS 920+
For guidance, thank you.

That error means the server could not transcode the file. Do you mean a Synology DS920+? If so, that device cannot transcode HDR content. Your video file is hevc HDR10 so if that needs to be transcoded, your server can’t do it so you will get that message.
I can’t tell why the video needs transcoding. You’ll need to play the file again and provide the logs from Plex for Windows, Windows/Mac app logs | Plex Support.
Plex Media Server.log (23.6 KB)
thanks。
Wrong logs. I need the ones from the Plex for Windows program. Click on the link I provided above to see how to find the correct logs.
Plex.log (86.7 KB)
thank you
Did you see the error before grabbing that log? I don’t see the error. I see you start to play a video, then your logs stops about 3 seconds later.
The only thing I noticed in your log is that the app is accessing your server with a remote connection. Check the video quality settings for “Internet Streaming”. The default is 2Mbps and that can cause a transocde.