# Java HiveMQ client error when starting on Raspberry Pi

**URL:** <https://community.hivemq.com/t/java-hivemq-client-error-when-starting-on-raspberry-pi/793>\
**Category:** HiveMQ Client Library\
**Created:** [October 28, 2021, 12:15pm UTC](https://community.hivemq.com/t/java-hivemq-client-error-when-starting-on-raspberry-pi/793 "2021-10-28T12:15:57Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![frank](https://avatars.discourse-cdn.com/v4/letter/f/3d9bf3/32.png) [@frank](https://community.hivemq.com/u/frank)\
**Post date:** [October 28, 2021, 12:15pm UTC](https://community.hivemq.com/t/java-hivemq-client-error-when-starting-on-raspberry-pi/793/1 "2021-10-28T12:15:57Z")

</div>

I’m experimenting with HiveMQ client in a Java application on the Raspberry Pi but get this error on start-up of my application:

```auto
[main] INFO io.netty.util.internal.PlatformDependent - Your platform does not provide complete low-level API for accessing direct buffers reliably. Unless explicitly requested, heap buffer will always be preferred to avoid potential system instability.
Exception in thread "main" java.lang.NoClassDefFoundError: sun/misc/Unsafe
	at jctools.core@2.1.2/org.jctools.util.UnsafeAccess.<clinit>(UnsafeAccess.java:46)
	at jctools.core@2.1.2/org.jctools.queues.BaseSpscLinkedArrayQueueConsumerField.<clinit>(BaseSpscLinkedArrayQueue.java:47)
	at com.hivemq.client.mqtt@1.2.2/com.hivemq.client.internal.mqtt.handler.publish.outgoing.MqttOutgoingQosHandler.<init>(MqttOutgoingQosHandler.java:92)

```

Any ideas what could be wrong?

---

<div class="post-metadata">

**Author:** ![frank](https://avatars.discourse-cdn.com/v4/letter/f/3d9bf3/32.png) [@frank](https://community.hivemq.com/u/frank)\
**Post date:** [October 28, 2021, 12:19pm UTC](https://community.hivemq.com/t/java-hivemq-client-error-when-starting-on-raspberry-pi/793/2 "2021-10-28T12:19:13Z")

</div>

And of course, right after posting this question, I found the answer on SO 😉

Needed to add this to module-info

```auto
requires jdk.unsupported;

```