It is likely the transocoder crash that is currently fixed in 1.32.6.7468 beta version if you want to install it. or you can wait til it goes public.
If you want to install either download from main website https://www.plex.tv/media-server-downloads/#plex-media-server or in the server general settings change the update channel to Beta and it will then download beta versions. ( you can set it back ti public after updating to this particular one with fix.
