Hello people, just wanted to share the fix to this as I didn’t find it anywhere else.
> ● openhab2.service - The openHAB 2 Home Automation Bus Solution
> Loaded: loaded (/lib/systemd/system/openhab2.service; enabled; vendor preset: enabled)
> Active: inactive (dead) (Result: exit-code) since Thu 2016-09-01 21:11:52 EST; 33s ago
> Docs: http://docs.openhab.org
> Process: 3101 ExecStart=/opt/openhab2/start.sh server (code=exited, status=200/CHDIR)
> Main PID: 3101 (code=exited, status=200/CHDIR)
> Sep 01 21:11:52 openHAB systemd[1]: openhab2.service: Unit entered failed state.
> Sep 01 21:11:52 openHAB systemd[1]: openhab2.service: Failed with result 'exit-code'.
> Sep 01 21:11:52 openHAB systemd[1]: openhab2.service: Service hold-off time over, scheduling restart.
> Sep 01 21:11:52 openHAB systemd[1]: Stopped The openHAB 2 Home Automation Bus Solution.
> Sep 01 21:11:52 openHAB systemd[1]: openhab2.service: Start request repeated too quickly.
> Sep 01 21:11:52 openHAB systemd[1]: Failed to start The openHAB 2 Home Automation Bus Solution.
After troubleshooting for a while, I noticed the file /lib/systemd/system/openhab2.service was pointing to /opt/openhab2 (manual installations) instead of /usr/share/openhab2 (repository installation, the way I installed) for no apparent reason, so I just corrected the 2 lines on the file showing the wrong path, ran sudo systemctl daemon-reload and sudo systemctl start openhab2, which solved the problem.
This was very weird tho, I am not really sure why the path would change, I never installed manually and didnt have any issues when restarting the service previously.
I am running OH2 on Ubuntu Server 16.04 LTS.
Hope this helps someone else.