Your vm may have suffered an unclean shutdown. Note "may". In absence of more info, a couple things to try.
If you have nodebb set up to be launched via systemd, disable that. And then stop just for good measure and then disable dependencies:
systemctl disable nodebb
systemctl stop nodebb
systemctl disable nginx (sub apache if using apache)
systemctl disable mongod (or whatever db backend you're using
Then reboot the vm. When it comes back up we're going to restart all that in reverse order, verifying each is up and running before proceeding to next:
systemctl status mongod
systemctl status nginx
systemctl status nodebb
Those should now all report "disabled". So let's start them up, verifying each launches w/o error before proceeding to next
systemctl start mongod
If the startup messages are greek to you or pass by too quickly:
systemctl status mongod
Should report something very close to this:
[root@forums ~]# systemctl status mongod
● mongod.service - MongoDB Database Server
Loaded: loaded (/usr/lib/systemd/system/mongod.service; enabled; vendor preset: disabled)
Active: active (running) since Fri 2021-03-05 06:57:52 UTC; 1 weeks 6 days ago
Docs: https://docs.mongodb.org/manual
Process: 457777 ExecStart=/usr/bin/mongod $OPTIONS (code=exited, status=0/SUCCESS)
Process: 457762 ExecStartPre=/usr/bin/chmod 0755 /var/run/mongodb (code=exited, status=0/SUCCESS)
Process: 457739 ExecStartPre=/usr/bin/chown mongod:mongod /var/run/mongodb (code=exited, status=0/SUCCESS)
Process: 457725 ExecStartPre=/usr/bin/mkdir -p /var/run/mongodb (code=exited, status=0/SUCCESS)
Main PID: 457824 (mongod)
CGroup: /system.slice/mongod.service
└─457824 /usr/bin/mongod -f /etc/mongod.conf
‣ 457824 /usr/bin/mongod -f /etc/mongod.conf
If that all looks good, try starting nodebb:
systemctl start nodebb
A status check should look something like this:
[root@forums ~]# systemctl status nodebb
● nodebb.service - NodeBB
Loaded: loaded (/etc/systemd/system/nodebb.service; enabled; vendor preset: disabled)
Active: active (running) since Fri 2021-03-05 06:59:17 UTC; 1 weeks 6 days ago
Docs: https://docs.nodebb.org
Process: 459055 ExecStart=/usr/bin/env node loader.js (code=exited, status=0/SUCCESS)
Main PID: 459071 (node)
CGroup: /system.slice/nodebb.service
├─459071 /usr/bin/node /opt/nodebb/loader.js
├─459082 /usr/bin/node /opt/nodebb/app.js
If you are getting anything other than "SUCCESS" then stop just be sure:
systemctl stop nodebb
Then sudo to change to your nodebb user and then go try starting nodebb manually using the "log" flag:
cd /where/ever/your/nodebb/lives
./nodebb start -l
Then copy/pasta the ensuing spewage so the other gurus in the lurking can deconstruct. Good luck.
Once you get this sorted, be sure to re-enable those services else they will not automatically restart after a shutdown/reboot.
systemctl enable mongod
systemctl enable nginx
systemctl enable nodebb
I'd even then reboot after that just to be sure all comes back up as expected.
Yeah, this is not issue specific but when dealing with unknown glitches it is nice to rule out some low hanging fruit to help isolate.