OpenHAB 3 ports are not open

  • Platform information:
    • Hardware: HP Microserver AMD Athlon™ II Neo N36L Dual-Core Processor, 2GB RAM
    • OS:Ubuntu Server 20.04 LTS
    • Java Runtime Environment:Zulu 11
    • openHAB version: 3
  • Issue of the topic: Openhab ports not opening

Fresh install of OpenHAB3, was working on it yesterday fine.
Manually migrating from openhab2 on a full fresh install of OS and OH.
Since this is a multi-use server, I also installed Unifi controller software (for Ubiquiti network device management, previously installed alongside openhab fine).

Unifi Controller uses ports:1443 and 8081 which are working fine.

Now the openhab service starts but it does not open any ports. No errors (nothing at all) in openhab.log.

Stopped/disabled unifi software, no change after restarting openhab and the server.

I was hoping to find something in the logs but can’t find any reason it’s not working.

● openhab.service - openHAB - empowering the smart home
 Loaded: loaded (/lib/systemd/system/openhab.service; enabled; vendor preset: enabled)
 Active: active (running) since Sat 2021-01-23 09:32:33 ACDT; 42s ago
   Main PID: 959 (java)
  Tasks: 38 (limit: 2129)
 Memory: 348.9M
 CGroup: /system.slice/openhab.service
         └─959 /usr/bin/java -XX:-UsePerfData -Dopenhab.home=/usr/share/openhab -Dopenhab.conf=/etc/openhab -Dopenhab.runtime=/usr/share/openhab/runtime -Dopenhab.userdata=/var/lib/openhab -Dop>

Jan 23 09:32:33 nas systemd[1]: Started openHAB - empowering the smart home.
lines 1-12/12 (END)

#>nmap localhost
Starting Nmap 7.80 ( ) at 2021-01-23 09:35 ACDT
Nmap scan report for localhost (
Host is up (0.00021s latency).
Not shown: 996 closed ports
22/tcp    open  ssh
139/tcp   open  netbios-ssn
445/tcp   open  microsoft-ds
10000/tcp open  snet-sensor-mgmt

Nmap done: 1 IP address (1 host up) scanned in 0.15 seconds

I worked it out - The Unifi installer pushes Java 8 so it broke Openhab3. Removed the old java and it was all good! Now to get unifi working on Java 11…

Caution: If I remember correctly UniFi requires Java 8. You may have to containerize something.