Looked at the logs - the first were without debug logging but the second set had debug logging. The server has been crashing with what appears to be similar crashes as reported on this forum topic Ubuntu 18.04.2 LTS - Plex Server Crashes - Double free or corruption (!prev)
The issue is still unresolved. It appears to arise sometimes when getting to the end of playback from a transcoded video. It is a timing bug where a couple of threads are dealing with requests from the app notifying end of playback - and some plex clients (eg Roku Plex app) send this indication in more than one way.
The last set of logs show a crash at 11:23:10 am on May 21st when playback stopped for remote user sewxxxxwithxxxndi on a Roku. A crash report was generated but the server process did not terminate and continued to run in cripple mode - eventually deadlocking and stopping to handle requests with the last completed request at 12:30. You eventually stopped the server at 21:21. The crash report was uploaded to our server at 21:23
The cause of this issue is yet to be identified. Attempts to reproduce in a debug environment have failed so far - I am liasing with the development to help identify the bug.
