Java error in log

I’ve googled this and searched the forum for this issue, but I can’t find any similar issue. What I’ve found is that it might be related to the IKEA Trådfri binding that I use, but I do not experience any issue with that or anything else for that matter. OpenHAB runs as expected but this error message is appearing multiple time a minute in the log.

Does anyone else experiencing the same issue or have an idea on how to solve it?

I run OpenHAB 2.1 stable release under Ubuntu server 17.04

2017-11-23 11:12:45.451 [WARN ] [e.californium.scandium.DTLSConnector] - Could not send datagram
java.net.SocketException: Protocol family unavailable
        at java.net.PlainDatagramSocketImpl.send(Native Method)[:1.8.0_151]
        at java.net.DatagramSocket.send(DatagramSocket.java:693)[:1.8.0_151]
        at org.eclipse.californium.scandium.DTLSConnector.sendFlight(DTLSConnector.java:1269)[194:scandium:1.0.5]
        at org.eclipse.californium.scandium.DTLSConnector.handleTimeout(DTLSConnector.java:1296 [194:scandium:1.0.5]
        at org.eclipse.californium.scandium.DTLSConnector.access$500(DTLSConnector.java:101)[194:scandium:1.0.5]
        at org.eclipse.californium.scandium.DTLSConnector$RetransmitTask.run(DTLSConnector.java:1412)[194:scandium:1.0.5]
        at java.util.TimerThread.mainLoop(Timer.java:555)[:1.8.0_151]
        at java.util.TimerThread.run(Timer.java:505)[:1.8.0_151]

A brief google search appears to indicate that this might be solvable by passing this argument to the JVM at startup:

-Djava.net.preferIPv4Stack=true

Thx for the advise, but it didn’t work. I have IPv6 turn off altogether on the server, so that shouldn’t be the issue anyway.

There were a lot of updates in the Tradfri binding and the Scandium library since the 2.1 release. Please try the latest 2.2 snapshot whether the problem still exist there or not.

I thought about doing that, but I can’t find where to download the snapshots. Can you provide me with a link?

Sure, they are right here: https://openhab.ci.cloudbees.com/job/openHAB-Distribution/