Plex is cool, but if your internet goes down, then your clients can’t always connect. So, back the the basics for me with ps3MediaServer as a backup:
sudo apt-get install mencoder tsmuxer avisynth ffmpeg mplayer
sudo apt-get install default-jre
Download generic-linux-unix from: https://sourceforge.net/projects/ps3mediaserver/files/
Change PMS.sh and tsmuxer to be executable if it is not
./PMS.sh (if you have more than one IP interface on your PC, bind it to your preferred one)