Jon plugin - failing RebuildIndex operation on [MassIndexer] component

RebuildIndex operation on [MassIndexer] component is failing while issuing in JON with this error:

java.lang.NullPointerException
at org.infinispan.rhq.CacheComponent.invokeOperation(CacheComponent.java:157)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at org.rhq.core.pc.inventory.ResourceContainer$ComponentInvocationThread.call(ResourceContainer.java:634)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
at java.util.concurrent.FutureTask.run(FutureTask.java:166)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
at java.lang.Thread.run(Thread.java:722)

I reused configuration from ISPN test suite + I was able to issue this operation successfully via jconsole tool. That's why I suspect that problems are somewhere in JON-ISPN interaction or plugin.