Rocket chat not working


Hi All,
I have already set up the rocketchat in my Centos VPS. it has worked a couple of weeks as normal.
but now I can’t run the rocketchat in my VPS I don’t know why this happened.
So i re-installed the rocketchat according to the documentation but still not working.

after I type this command

systemctl status rocketchat

● rocketchat.service - Rocket.Chat server
Loaded: loaded (/etc/systemd/system/rocketchat.service; enabled; vendor preset: disabled)
Active: failed (Result: exit-code) since Wed 2018-11-28 15:06:01 AEDT; 1h 6min ago
Process: 50733 ExecStart=/usr/local/bin/node /opt/rocket/Rocket.Chat/main.js (code=exited, status=217/USER)
Main PID: 50733 (code=exited, status=217/USER)

Nov 28 15:06:01 systemd[1]: Started Rocket.Chat server.
Nov 28 15:06:01 systemd[1]: Starting Rocket.Chat server…
Nov 28 15:06:01 systemd[1]: rocketchat.service: main process exited, code=exited, status=217/USER
Nov 28 15:06:01 systemd[1]: Unit rocketchat.service entered failed state.
Nov 28 15:06:01 systemd[1]: rocketchat.service failed.

this is my rocketchat.service file

Description=The Rocket.Chat server
ExecStart=/usr/local/bin/node /opt/Rocket.Chat/main.js
Environment=MONGO_URL=mongodb://localhost:27017/rocketchat ROOT_URL= PORT=3000

and I can’t run the home page of rocketchat with curl

curl http://localhost:3000
curl: (7) Failed connect to localhost:3000; Connection refused

Mongo db is currently working perfectly

please help me :frowning: