Error on Java web socket implementation

Question

I'm connecting to a web socket server via my Java application using Grizzly web socket implementation.

@OnError
public void error(Session session, Throwable t) {
    Log4Me.getLogger().debug("WebSocket Error {} on session {} ", session, t);
    Log4Me.getLogger().error("Error on session {}, Exception:{}", session.getId(), t.getMessage());

}

@OnClose
public void closedConnection(Session session, CloseReason reason) {
    Log4Me.getLogger().info("Session closed. session: {}, Reason {}", session, reason);
}

@OnMessage
public void onMessage(Session session, ByteBuffer message) {
}

@OnOpen
public void onOpen(Session session) {
}

Most of the time it works as expected but sometimes the onError callback is caled. When I run the application after removing the @OnError annotation, I get an exception:

at sun.reflect.GeneratedMethodAccessor43.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.glassfish.tyrus.core.AnnotatedEndpoint.callMethod(AnnotatedEndpoint.java:477)
at org.glassfish.tyrus.core.AnnotatedEndpoint.access$100(AnnotatedEndpoint.java:87)
at org.glassfish.tyrus.core.AnnotatedEndpoint$WholeHandler$1.onMessage(AnnotatedEndpoint.java:573)
at org.glassfish.tyrus.core.TyrusSession.notifyMessageHandlers(TyrusSession.java:562)
at org.glassfish.tyrus.core.TyrusEndpointWrapper.onMessage(TyrusEndpointWrapper.java:758)
at org.glassfish.tyrus.core.TyrusWebSocket.onMessage(TyrusWebSocket.java:187)
at org.glassfish.tyrus.core.frame.BinaryFrame.respond(BinaryFrame.java:93)
at org.glassfish.tyrus.core.ProtocolHandler.process(ProtocolHandler.java:635)
at org.glassfish.tyrus.client.TyrusClientEngine$TyrusReadHandler.handle(TyrusClientEngine.java:664)
at org.glassfish.tyrus.container.grizzly.client.GrizzlyClientFilter$ProcessTask.execute(GrizzlyClientFilter.java:472)
at org.glassfish.tyrus.container.grizzly.client.TaskProcessor.processTask(TaskProcessor.java:114)
at org.glassfish.tyrus.container.grizzly.client.TaskProcessor.processTask(TaskProcessor.java:91)
at org.glassfish.tyrus.container.grizzly.client.GrizzlyClientFilter.handleRead(GrizzlyClientFilter.java:270)
at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:284)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:201)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:133)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:112)
at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:561)
at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:112)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:117)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:56)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:137)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:565)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:545)
at java.lang.Thread.run(Thread.java:745)

It seems that it is trying to call a method of my class but it fails.. But I don't know any idea why it fails to the error case...
Any idea?

Thanks