org.directwebremoting.extend.MarshallException

Este ano de 2011, encontrei esse problema ao utilizar o DWR e identifiquei a causa raiz como a ausência de métodos get/set para propriedades anotadas como @RemoteProperty. Ao tentar estabelecer a comunicação javascript -> Java acontecia esse erro.
#ficaadica


AVISO: Marshalling exception
org.directwebremoting.extend.MarshallException: Error marshalling objeto.Model: null. See the logs for more details.
        at org.directwebremoting.impl.PropertyDescriptorProperty.setValue(PropertyDescriptorProperty.java:89)
        at org.directwebremoting.convert.BasicObjectConverter.convertInbound(BasicObjectConverter.java:140)
        at org.directwebremoting.dwrp.DefaultConverterManager.convertInbound(DefaultConverterManager.java:159)
        at org.directwebremoting.dwrp.BaseCallMarshaller.marshallInbound(BaseCallMarshaller.java:155)
        at org.directwebremoting.servlet.PlainCallHandler.handle(PlainCallHandler.java:44)
        at org.directwebremoting.servlet.UrlProcessor.handle(UrlProcessor.java:101)
        at org.directwebremoting.servlet.DwrServlet.doPost(DwrServlet.java:146)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:754)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:847)
        at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1523)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:279)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:188)
        at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:641)
        at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:97)
        at com.sun.enterprise.web.PESessionLockingStandardPipeline.invoke(PESessionLockingStandardPipeline.java:85)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:185)
        at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:325)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:226)
        at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:165)
        at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:791)
        at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:693)
        at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:954)
        at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:170)
        at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:135)
        at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:102)
        at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:88)
        at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:76)
        at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:53)
        at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:57)
        at com.sun.grizzly.ContextTask.run(ContextTask.java:69)
        at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:330)
        at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:309)
        at java.lang.Thread.run(Thread.java:662)
Caused by: java.lang.IllegalArgumentException
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at org.directwebremoting.impl.PropertyDescriptorProperty.setValue(PropertyDescriptorProperty.java:81)
        ... 32 more

AVISO: --Erroring: batchId[2] message[org.directwebremoting.extend.MarshallException: Error marshalling com.vivo.smap.novosmapfalhas.model.SmapFiltroModel: null. See the logs for more details.]