This error message indicates some difficulty with either access permissions or codec downloads. It could also be caused by a too low inotify table size.
Jul 28, 2022 04:36:25.001 [0x7f7fed852b38] ERROR - [Req#72bb1e] [Transcoder] Error while decoding stream #0:1: I/O error
Jul 28, 2022 04:36:28.000 [0x7f7fecce6b38] ERROR - [Req#72bb1f] [Transcoder] [eac3_eae @ 0x7f24e48c5040] EAE timeout! EAE not running, or wrong folder? Could not read '/var/packages/PlexMediaServer/shares/PlexMediaServer/AppData/tmp/pms-53ff86a0-fe98-406f-9b40-d564aa72e68c/EasyAudioEncoder/Convert to WAV (to 8ch or less)/02b9beb2-a801-4ca1-a646-565d25776e88_27755-0-1619.wav'
I recommend you to dive into the threads which deal with the “peculiarities” of Plex on Synology, particularly with the changes brought in DSM 7.
If you are used to operate Plex Server on Windows, take some extra time to learn the general principles of Linux platforms.
