システムサービスが失敗しました

何の理由もなくNzbgetが動作を停止したと思いました。何の変更もせず、サービスが停止し、再起動が拒否されました。

 sudo systemctl status nzbget -l
 * nzbget.service - NZBGet Daemon
 Loaded: loaded (/etc/systemd/system/nzbget.service; enabled)
 Active: failed (Result: start-limit) since Sun 2016-05-01 06:23:27 BST; 2min 46s ago
Process: 596 ExecStop=/opt/nzbget/nzbget -Q (code=exited, status=0/SUCCESS)  Process: 586 ExecStart=/opt/nzbget/nzbget -c /opt/nzbget/nzbget.conf -D (code=exited, status=0/SUCCESS)
 Main PID: 588 (code=killed, signal=ABRT)

May 01 06:23:27 osmc systemd[1]: Unit nzbget.service entered failed state.
May 01 06:23:27 osmc systemd[1]: nzbget.service start request repeated too quickly, refusing to start.
May 01 06:23:27 osmc systemd[1]: Failed to start NZBGet Daemon.
May 01 06:23:27 osmc systemd[1]: Unit nzbget.service entered failed state.

これはログです。

osmc@osmc:~/Downloads$ 
cat nzbget.log 
Sun May 1 06:38:44 2016 INFO nzbget 16.4 daemon-mode 
Sun May 1 06:38:44 2016 INFO nzbget 16.4 daemon-mode 
Sun May 1 06:38:45 2016 INFO nzbget 16.4 daemon-mode 
Sun May 1 06:38:45 2016 INFO nzbget 16.4 daemon-mode 
Sun May 1 06:38:46 2016 INFO nzbget 16.4 daemon-mode

これがまさにサービスです。

[Unit]
Description=NZBGet Daemon
After=network.target
RequiresMountsFor=/mnt/

[Service]
User=osmc
Group=osmc
Type=forking
ExecStart=/opt/nzbget/nzbget -c /opt/nzbget/nzbget.conf -D
ExecStop=/opt/nzbget/nzbget -Q
ExecReload=/opt/nzbget/nzbget -O
KillMode=process
Restart=on-failure

[Install]
WantedBy=multi-user.target