To add to @borpin’s reply, could you copy and paste here the result of trying to restart emonhub via SSH?
sudo systemctl restart emonhub
sudo systemctl status emonhub
This is the thread @borpin was referring too that both Glyn and I had suffered a potentially similar issue after a power cut: Backup module usb-import.sh script (beta) - #9 by TrystanLea