Erreur de Glassfish lors de la production de JSON

j'ai développé une application Android et maintenant je commence avec sa DB externe et son serveur, la communication est effectuée par RESTful web services.

cette application Android ne produit et consomme que des informations dans JSON, donc dans Mes façades de services web Je veux juste effacer toute mention au XML dans les méthodes CRUD, (automatiquement généré par NetBeans).

je veux dire, à partir de ceci:

@GET
@Override
@Produces({MediaType.APPLICATION_XML, MediaType.APPLICATION_JSON})
public List<Counselor> findAll() {
    return super.findAll();
}

(sans le MediaType.APPLICATION_XML):

@GET
@Override
@Produces(MediaType.APPLICATION_JSON)
public List<Counselor> findAll() {
    return super.findAll();
}

le truc c'est que quand je déploie ces modifications dans mon serveur GlassFish (4.1.1) et que je fais quelques tests avec mon navigateur (je veux juste voir mes données DB) je reçois une erreur avec ce stacktrace:

java.lang.NoClassDefFoundError: Could not initialize class org.eclipse.persistence.jaxb.BeanValidationHelper
    at org.eclipse.persistence.jaxb.JAXBBeanValidator.isConstrainedObject(JAXBBeanValidator.java:257)
    at org.eclipse.persistence.jaxb.JAXBBeanValidator.shouldValidate(JAXBBeanValidator.java:208)
    at org.eclipse.persistence.jaxb.JAXBMarshaller.validateAndTransformIfNeeded(JAXBMarshaller.java:587)
    at org.eclipse.persistence.jaxb.JAXBMarshaller.marshal(JAXBMarshaller.java:481)
    at org.eclipse.persistence.jaxb.rs.MOXyJsonProvider.writeTo(MOXyJsonProvider.java:949)
    at org.glassfish.jersey.message.internal.WriterInterceptorExecutor$TerminalWriterInterceptor.invokeWriteTo(WriterInterceptorExecutor.java:265)
    at org.glassfish.jersey.message.internal.WriterInterceptorExecutor$TerminalWriterInterceptor.aroundWriteTo(WriterInterceptorExecutor.java:250)
    at org.glassfish.jersey.message.internal.WriterInterceptorExecutor.proceed(WriterInterceptorExecutor.java:162)
    at org.glassfish.jersey.server.internal.JsonWithPaddingInterceptor.aroundWriteTo(JsonWithPaddingInterceptor.java:106)
    at org.glassfish.jersey.message.internal.WriterInterceptorExecutor.proceed(WriterInterceptorExecutor.java:162)
    at org.glassfish.jersey.server.internal.MappableExceptionWrapperInterceptor.aroundWriteTo(MappableExceptionWrapperInterceptor.java:86)
    at org.glassfish.jersey.message.internal.WriterInterceptorExecutor.proceed(WriterInterceptorExecutor.java:162)
    at org.glassfish.jersey.message.internal.MessageBodyFactory.writeTo(MessageBodyFactory.java:1130)
    at org.glassfish.jersey.server.ServerRuntime$Responder.writeResponse(ServerRuntime.java:683)
    at org.glassfish.jersey.server.ServerRuntime$Responder.processResponse(ServerRuntime.java:424)
    at org.glassfish.jersey.server.ServerRuntime$Responder.process(ServerRuntime.java:414)
    at org.glassfish.jersey.server.ServerRuntime.run(ServerRuntime.java:312)
    at org.glassfish.jersey.internal.Errors.call(Errors.java:271)
    at org.glassfish.jersey.internal.Errors.call(Errors.java:267)
    at org.glassfish.jersey.internal.Errors.process(Errors.java:315)
    at org.glassfish.jersey.internal.Errors.process(Errors.java:297)
    at org.glassfish.jersey.internal.Errors.process(Errors.java:267)
    at org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:317)
    at org.glassfish.jersey.server.ServerRuntime.process(ServerRuntime.java:292)
    at org.glassfish.jersey.server.ApplicationHandler.handle(ApplicationHandler.java:1139)
    at org.glassfish.jersey.servlet.WebComponent.service(WebComponent.java:460)
    at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:386)
    at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:334)
    at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:221)
    at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:318)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160)
    at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:734)
    at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:673)
    at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:174)
    at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:416)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:283)
    at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:459)
    at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:167)
    at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:206)
    at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:180)
    at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:235)
    at org.glassfish.grizzly.filterchain.ExecutorResolver.execute(ExecutorResolver.java:119)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:283)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:200)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:132)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:111)
    at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
    at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:536)
    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.access0(WorkerThreadIOStrategy.java:56)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:137)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:591)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:571)
    at java.lang.Thread.run(Thread.java:745)

Toute idée de ce?

j'espère m'expliquer...merci à l'avance!!