I found this in your log
Dec 23, 2022 14:44:37.964 [10048] INFO - [MPVEngine/mpv] cplayer: (+) Audio --aid=1 (*) (mp3 2ch 44100Hz)
Dec 23, 2022 14:44:37.964 [10048] DEBUG - [MPVEngine/mpv] ad: Codec list:
Dec 23, 2022 14:44:37.964 [10048] DEBUG - [MPVEngine/mpv] ad: mp3 - MP3 (MPEG audio layer 3)
Dec 23, 2022 14:44:37.964 [10048] DEBUG - [MPVEngine/mpv] ad: Opening decoder mp3
Dec 23, 2022 14:44:37.965 [10048] DEBUG - [MPVEngine/mpv] ad: Requesting 1 threads for decoding.
Dec 23, 2022 14:44:37.965 [10048] DEBUG - [MPVEngine/mpv] ad: Selected codec: mp3 (MP3 (MPEG audio layer 3))
Dec 23, 2022 14:44:37.965 [10048] DEBUG - [MPVEngine/mpv] af: User filter list:
Dec 23, 2022 14:44:37.965 [10048] DEBUG - [MPVEngine/mpv] af: lavcac3enc (ac3)
Dec 23, 2022 14:44:37.965 [10048] DEBUG - [MPVEngine/mpv] cplayer: Starting playback...
It is trying to use the lavcac3enc (ac3) encoder, which seems to cause some issues with newer version of Plex Desktop/Plex HTPC. It sounds a bit like Plex HTPC Frozen Playback with Latest Release (only some files).
Yes, they are related. They both use the same playback engine (mpv), therefore tips for Plex HTPC can be applied to Plex Desktop in most cases. Like changing the mpv.dll.
Okay, well the standalone mpv version is not bundled with Plex. You have to download it separately => Releases · shinchiro/mpv-winbuild-cmake · GitHub
Unzip the archive (Use mpv-x86_64-20230105-git-3a6ef81 if you are unsure which one to use) and open a terminal.
Run mpv.com file.mkv -v to see if it actually works with the absolute default mpv settings, from there on we can add options used by Plex and determine when it breaks.
