I recently installed Plex (126.96.36.19925) on Linux Mint 18 and configured it according to this article
Everything works fine except for DLNA. When I boot up, DLNA does not work. Only after I manually issue a
sudo service plexmediaserver restart
does DLNA start working.
When DLNA is not working, no DLNA client can find/discover or connect to Plex. I have several clients that I use to test (PS3, Android apps, etc.)
I haven't found anything in the log files that would suggest why DLNA is not running properly.
DLNA appears to start up correctly, according to the log files:
Oct 24, 2017 17:09:54.466 [0x7f94acfff700] DEBUG - Plex DLNA Server starting.
Oct 24, 2017 17:09:54.466 [0x7f94acfff700] DEBUG - Job running: '/usr/lib/plexmediaserver/Plex DLNA Server'
But the log files say the same thing no matter if it's right after a system start or after a manual service restart.
I don't see any relevant errors in the log files that would suggest what is happening.
When DLNA is not working, I get the same result from calling this as when DLNA is working:
sudo service plexmediaserver status
It always says it's active...so, nothing odd there.