It sounds like a “deadlock” issue, multiple people having it including me. The thread where we are discussing it is here: Plex Server Crashing Randomly - #89 by Jesperhk
There is a little more logging needed to identify the issue if it is a “deadlock”. I outlined the process from a Plex employee, if you are willing to help with diagnosing it, the Plex team member is named “sa2000” if you want to send your logs, connection list, and dump file to him.
