I install Plex Media server with this guide on Odroid C2 with Ubuntu 16.04.5 and i have this error:
/usr/lib/plexmediaserver/Plex Tuner Service: error while loading shared libraries: libstdc++.so.6: cannot open shared object file: No such file or directory
The ODROID-C2 Linux support is very bad. It’s basically an Android device, not general Linux. You won’t be able to use Plex DVR. Everything else should just work, even with this error. So what exactly is your question?