dnscrypt-proxy 无法在 17.10 上启动

我从 repo 安装了 dnscrypt-proxy。我没有碰任何配置。这是错误消息

$ systemctl  status dnscrypt-proxy.service
● dnscrypt-proxy.service - DNSCrypt client proxy
   Loaded: loaded (/lib/systemd/system/dnscrypt-proxy.service; enabled; vendor preset: enabled)
   Active: failed (Result: exit-code) since ; 10s ago
     Docs: man:dnscrypt-proxy(8)
  Process: 20935 ExecStart=/usr/sbin/dnscrypt-proxy /etc/dnscrypt-proxy/dnscrypt-proxy.conf (code=exited, status=1/FAILURE)
 Main PID: 20935 (code=exited, status=1/FAILURE)

systemd[1]: dnscrypt-proxy.service: Unit entered failed state.
systemd[1]: dnscrypt-proxy.service: Failed with result 'exit-code'.
systemd[1]: dnscrypt-proxy.service: Service hold-off time over, scheduling restart.
systemd[1]: Stopped DNSCrypt client proxy.
systemd[1]: dnscrypt-proxy.service: Start request repeated too quickly.
systemd[1]: Failed to start DNSCrypt client proxy.
systemd[1]: dnscrypt-proxy.service: Unit entered failed state.
systemd[1]: dnscrypt-proxy.service: Failed with result 'exit-code'.

$ cat /lib/systemd/system/dnscrypt-proxy.service
[Unit]
Description=DNSCrypt client proxy
Documentation=man:dnscrypt-proxy(8)
Requires=dnscrypt-proxy.socket
After=network.target
Before=nss-lookup.target

[Install]
Also=dnscrypt-proxy.socket
WantedBy=multi-user.target

[Service]
Type=notify
NonBlocking=true
User=_dnscrypt-proxy
ExecStart=/usr/sbin/dnscrypt-proxy /etc/dnscrypt-proxy/dnscrypt-proxy.conf
Restart=always
ProtectSystem=strict
ProtectHome=true
ProtectKernelModules=true
ProtectKernelTunables=true
ProtectControlGroups=true
MemoryDenyWriteExecute=true
RestrictRealtime=true

编辑：操作系统重启以某种方式解决它。
编辑：不，再次重新启动后，问题又回来了。尝试了 systemctl restart 和 OS restart。