After which you have to follow the straightforward systemd service troubleshooting procedure: systemctl is-system-running systemctl list-units systemctl

After which you have to follow the straightforward systemd service troubleshooting procedure: systemctl is-system-running systemctl list-units systemctl list-units -t service --all systemctl list-units --state failed systemctl is-failed light.service systemctl status light.service systemctl show light.service journalctl -u light.service systemctl restart light.service journalctl -u light.service systemctl stop light.service SYSTEMD_LOG_LEVEL=debug /lib/systemd/systemd-lightd journalctl -u light.service reboot systemctl --force reboot echo r > /proc/sysrq-trigger echo e > /proc/sysrq-trigger echo i > /proc/sysrq-trigger echo s > /proc/sysrq-trigger echo u > /proc/sysrq-trigger echo b > /proc/sysrq-trigger