SOLVED: Jellyfin service not starting

[TheDreadPirate]

What is all his stuff where you are creating jellyfin.sh?  What is in it?

Open this file and show me what the contents are.

/etc/systemd/system/multi-user.target.wants/jellyfin.service

As follows. 

[Unit]
Description=Jellyfin
After=network.target

[Service]
Type=simple
User=jellyfin
Restart=always
ExecStart=/lib/jellyfin/jellyfin.sh

[Install]
WantedBy=multi-user.target

I'm wondering if apt purge doesn't remove this file.  Because this file is wrong (ExecStart primarily), I'm assuming from when you were editing it. Which I'm assuming since you opened it with nano.

Here is mine.  Copy and paste it into yours and try to start the service again.

[Unit]
Description = Jellyfin Media Server
After = network-online.target

[Service]
Type = simple
EnvironmentFile = /etc/default/jellyfin
User = jellyfin
Group = jellyfin
WorkingDirectory = /var/lib/jellyfin
ExecStart = /usr/bin/jellyfin $JELLYFIN_WEB_OPT $JELLYFIN_RESTART_OPT $JELLYFIN_FFMPEG_OPT $JELLYFIN_SERVICE_OPT $JELLYFIN_NOWEBAPP_OPT $JELLYFIN_ADDITIONAL_OPTS
Restart = on-failure
TimeoutSec = 15
SuccessExitStatus=0 143

[Install]
WantedBy = multi-user.target