Hi there @krishnannavadia ,

If you would like to debug this, take a look at the output above. You should run the systemctl command would you like to get some more information.

For example, when the service is running normally you would see this:

# systemctl status nginx.service
● nginx.service - nginx - high performance web server
   Loaded: loaded (/usr/lib/systemd/system/nginx.service; enabled; vendor preset: disabled)
   Active: active (running) since Thu 2020-04-09 13:48:50 UTC; 1s ago
     Docs: http://nginx.org/en/docs/
  Process: 26490 ExecStop=/bin/kill -s TERM $MAINPID (code=exited, status=0/SUCCESS)
  Process: 26524 ExecStart=/usr/sbin/nginx -c /etc/nginx/nginx.conf (code=exited, status=0/SUCCESS)
 Main PID: 26525 (nginx)
   CGroup: /system.slice/nginx.service
           ├─26525 nginx: master process /usr/sbin/nginx -c /etc/nginx/nginx.conf
           ├─26526 nginx: worker process
           ├─26527 nginx: worker process
           ├─26528 nginx: worker process
           ├─26529 nginx: worker process
           ├─26530 nginx: worker process
           ├─26531 nginx: worker process
           ├─26532 nginx: worker process
           ├─26533 nginx: worker process
           ├─26534 nginx: cache manager process
           └─26535 nginx: cache loader process

If not, you might see errors and you can debug the issues this way:

# systemctl status nginx.service
● nginx.service - nginx - high performance web server
   Loaded: loaded (/usr/lib/systemd/system/nginx.service; enabled; vendor preset: disabled)
   Active: active (running) since Thu 2020-04-09 13:48:50 UTC; 1s ago
     Docs: http://nginx.org/en/docs/
  Process: 26490 ExecStop=/bin/kill -s TERM $MAINPID (code=exited, status=0/SUCCESS)
  Process: 26524 ExecStart=/usr/sbin/nginx -c /etc/nginx/nginx.conf (code=exited, status=0/SUCCESS)
 Main PID: 26525 (nginx)
   CGroup: /system.slice/nginx.service
           ├─26525 nginx: master process /usr/sbin/nginx -c /etc/nginx/nginx.conf
           ├─26526 nginx: worker process
           ├─26527 nginx: worker process
           ├─26528 nginx: worker process
           ├─26529 nginx: worker process
           ├─26530 nginx: worker process
           ├─26531 nginx: worker process
           ├─26532 nginx: worker process
           ├─26533 nginx: worker process
           ├─26534 nginx: cache manager process
           └─26535 nginx: cache loader process

Apr 09 13:48:50 domain.com nginx[26524]: nginx: [warn] the "ssl" directive is deprecated, use the "listen ... ssl" directive instead in /etc/nginx/conf.d/...l.conf:148
Apr 09 13:48:50 domain.com nginx[26524]: nginx: [warn] the "ssl" directive is deprecated, use the "listen ... ssl" directive instead in /etc/nginx/conf.d/...ssl.conf:9
Apr 09 13:48:15 domain.com systemd[1]: nginx.service: control process exited, code=exited status=1
Apr 09 13:48:15 domain.com systemd[1]: Failed to start nginx - high performance web server.
Apr 09 13:48:15 domain.com systemd[1]: Unit nginx.service entered failed state.
Apr 09 13:48:15 domain.com systemd[1]: nginx.service failed.