Rocket.chat not loading after new installation on ubuntu 18

Description

Hi i have installed rocketchat server manually as per steps provided on official site and getting gray screen only when trying to access it.

Service file content:
[Unit]
Description=The Rocket.Chat server
After=network.target remote-fs.target nss-lookup.target mongod.target mongod.service apache2.service
[Service]
ExecStart=/usr/local/bin/node /opt/Rocket.Chat/main.js
StandardOutput=syslog
StandardError=syslog
SyslogIdentifier=rocketchat
User=rocketchat
Environment=LD_PRELOAD=/opt/Rocket.Chat/programs/server/npm/node_modules/sharp/vendor/lib/libz.so
Environment=NODE_ENV=production
Environment=MONGO_URL=mongodb://localhost:27017/rocketchat
Environment=MONGO_OPLOG_URL=mongodb://localhost:27017/local
Environment=ROOT_URL=https://chat.domain.com/
Environment=PORT=3000
[Install]
WantedBy=multi-user.target

Server Setup Information

  • Version of Rocket.Chat Server: 4.2.0
  • Operating System: Ubuntu 18
  • Deployment Method: Manual
  • Number of Running Instances: 1
  • DB Replicaset Oplog: Enabled
  • NodeJS Version: 12.18.4
  • MongoDB Version: 4.0
  • Proxy: apache
  • Firewalls involved: No

Any additional Information