Hi,
Please advice where to look for clue what may gone wrong. I got newly deployed HTPC running Lubuntu 18.04. All configured following instructions present here. I got my library stored on mounted ntfs drive (/media/stuff/Plex/Plex Media Server) and override.conf with correct route to this location. Also PMS is running with my root user.
All were fine for couple a weeks with planned reboots and shutdowns, when today after unexpected power outage at home HTPC rebooted but plex didnt start as before.
Here’s result of systemctl status plexmediaserver
● plexmediaserver.service - Plex Media Server for Linux
Loaded: loaded (/lib/systemd/system/plexmediaserver.service; enabled; vendor preset: enabled)
Drop-In: /etc/systemd/system/plexmediaserver.service.d
└─override.conf
Active: failed (Result: exit-code) since Mon 2018-09-03 16:30:17 MSK; 35min ago
Process: 1640 ExecStart=/bin/sh -c LD_LIBRARY_PATH=/usr/lib/plexmediaserver "/usr/lib/plexmediaserver/Plex Media Server" (code=exited, status=1/FAILURE)
Process: 1638 ExecStartPre=/bin/sh -c /usr/bin/test -d "${PLEX_MEDIA_SERVER_APPLICATION_SUPPORT_DIR}" || /bin/mkdir -p "${PLEX_MEDIA_SERVER_APPLICATION_SUPPORT_DIR}" (code=exited, status=0/SUCCESS)
Main PID: 1640 (code=exited, status=1/FAILURE)
сен 03 16:30:17 zHTPC systemd[1]: plexmediaserver.service: Service hold-off time over, scheduling restart.
сен 03 16:30:17 zHTPC systemd[1]: plexmediaserver.service: Scheduled restart job, restart counter is at 3.
сен 03 16:30:17 zHTPC systemd[1]: Stopped Plex Media Server for Linux.
сен 03 16:30:17 zHTPC systemd[1]: plexmediaserver.service: Start request repeated too quickly.
сен 03 16:30:17 zHTPC systemd[1]: plexmediaserver.service: Failed with result 'exit-code'.
сен 03 16:30:17 zHTPC systemd[1]: Failed to start Plex Media Server for Linux.
It looks to me, that PMS do not read settings of override file. Please help 
P.S. If some additional logs will help it - please tell me how to get it 
