Hi, I was wondering if anyone might be able to help me understand why I intermittently see this error: 2008-01-30 19:05:31,749 ERROR [ejb3.cache.simple.SimpleStatefulCache.ReportController] problem passivation thread | javax.ejb.EJBException: Could not passivate; failed to save state | at org.jboss.ejb3.cache.simple.StatefulSessionFilePersistenceManager.passivateSession(StatefulSessionFilePersistenceManager.java:406) | at org.jboss.ejb3.cache.simple.SimpleStatefulCache.passivate(SimpleStatefulCache.java:301) | at org.jboss.ejb3.cache.simple.SimpleStatefulCache$SessionTimeoutTask.run(SimpleStatefulCache.java:209) | Caused by: java.io.IOException | at org.jboss.serial.persister.RegularObjectPersister.writeSlotWithMethod(RegularObjectPersister.java:129) | at org.jboss.serial.persister.RegularObjectPersister.defaultWrite(RegularObjectPersister.java:86) | at org.jboss.serial.persister.RegularObjectPersister.writeData(RegularObjectPersister.java:62) | at org.jboss.serial.objectmetamodel.ObjectDescriptorFactory.describeObject(ObjectDescriptorFactory.java:276) | at org.jboss.serial.objectmetamodel.DataContainer$DataContainerDirectOutput.writeObject(DataContainer.java:206) | at org.jboss.serial.persister.RegularObjectPersister.writeSlotWithFields(RegularObjectPersister.java:182) | at org.jboss.serial.persister.RegularObjectPersister.defaultWrite(RegularObjectPersister.java:90) | at org.jboss.serial.persister.RegularObjectPersister.writeData(RegularObjectPersister.java:62) | at org.jboss.serial.objectmetamodel.ObjectDescriptorFactory.describeObject(ObjectDescriptorFactory.java:276) | at org.jboss.serial.objectmetamodel.DataContainer$DataContainerDirectOutput.writeObject(DataContainer.java:206) | at org.jboss.serial.persister.RegularObjectPersister.writeSlotWithFields(RegularObjectPersister.java:182) | at org.jboss.serial.persister.RegularObjectPersister.defaultWrite(RegularObjectPersister.java:90) | at org.jboss.serial.persister.RegularObjectPersister.writeData(RegularObjectPersister.java:62) | at org.jboss.serial.objectmetamodel.ObjectDescriptorFactory.describeObject(ObjectDescriptorFactory.java:276) | at org.jboss.serial.objectmetamodel.DataContainer$DataContainerDirectOutput.writeObject(DataContainer.java:206) | at org.jboss.serial.persister.ArrayPersister.saveObjectArray(ArrayPersister.java:110) | at org.jboss.serial.persister.ArrayPersister.writeData(ArrayPersister.java:101) | at org.jboss.serial.objectmetamodel.ObjectDescriptorFactory.describeObject(ObjectDescriptorFactory.java:276) | at org.jboss.serial.objectmetamodel.DataContainer$DataContainerDirectOutput.writeObject(DataContainer.java:206) | at org.jboss.serial.io.JBossObjectOutputStream.writeObjectOverride(JBossObjectOutputStream.java:181) | at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:322) | at org.jboss.serial.io.MarshalledObject.<init>(MarshalledObject.java:51) | at org.jboss.ejb3.stateful.StatefulBeanContext.writeExternal(StatefulBeanContext.java:842) | at org.jboss.serial.persister.ExternalizePersister.writeData(ExternalizePersister.java:58) | at org.jboss.serial.objectmetamodel.ObjectDescriptorFactory.describeObject(ObjectDescriptorFactory.java:276) | at org.jboss.serial.objectmetamodel.DataContainer$DataContainerDirectOutput.writeObject(DataContainer.java:206) | at org.jboss.serial.io.JBossObjectOutputStream.writeObjectOverride(JBossObjectOutputStream.java:181) | at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:322) | at org.jboss.ejb3.cache.simple.StatefulSessionFilePersistenceManager.passivateSession(StatefulSessionFilePersistenceManager.java:390) | ... 2 more | Caused by: java.lang.reflect.InvocationTargetException | 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.jboss.serial.persister.RegularObjectPersister.writeSlotWithMethod(RegularObjectPersister.java:120) | at org.jboss.serial.persister.RegularObjectPersister.defaultWrite(RegularObjectPersister.java:86) | at org.jboss.serial.persister.RegularObjectPersister.writeData(RegularObjectPersister.java:62) | at org.jboss.serial.objectmetamodel.ObjectDescriptorFactory.describeObject(ObjectDescriptorFactory.java:276) | at org.jboss.serial.objectmetamodel.DataContainer$DataContainerDirectOutput.writeObject(DataContainer.java:206) | at org.jboss.serial.persister.RegularObjectPersister.writeSlotWithFields(RegularObjectPersister.java:182) | at org.jboss.serial.persister.RegularObjectPersister.defaultWrite(RegularObjectPersister.java:90) | at org.jboss.serial.persister.RegularObjectPersister.writeData(RegularObjectPersister.java:62) | at org.jboss.serial.objectmetamodel.ObjectDescriptorFactory.describeObject(ObjectDescriptorFactory.java:276) | at org.jboss.serial.objectmetamodel.DataContainer$DataContainerDirectOutput.writeObject(DataContainer.java:206) | at org.jboss.serial.persister.RegularObjectPersister.writeSlotWithFields(RegularObjectPersister.java:182) | at org.jboss.serial.persister.RegularObjectPersister.defaultWrite(RegularObjectPersister.java:90) | at org.jboss.serial.persister.RegularObjectPersister.writeData(RegularObjectPersister.java:62) | at org.jboss.serial.objectmetamodel.ObjectDescriptorFactory.describeObject(ObjectDescriptorFactory.java:276) | at org.jboss.serial.objectmetamodel.DataContainer$DataContainerDirectOutput.writeObject(DataContainer.java:206) | at org.jboss.serial.persister.ArrayPersister.saveObjectArray(ArrayPersister.java:110) | at org.jboss.serial.persister.ArrayPersister.writeData(ArrayPersister.java:101) | at org.jboss.serial.objectmetamodel.ObjectDescriptorFactory.describeObject(ObjectDescriptorFactory.java:276) | at org.jboss.serial.objectmetamodel.DataContainer$DataContainerDirectOutput.writeObject(DataContainer.java:206) | at org.jboss.serial.io.JBossObjectOutputStream.writeObjectOverride(JBossObjectOutputStream.java:181) | at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:322) | at org.jboss.serial.io.MarshalledObject.<init>(MarshalledObject.java:51) | at org.jboss.ejb3.stateful.StatefulBeanContext.writeExternal(StatefulBeanContext.java:842) | at org.jboss.serial.persister.ExternalizePersister.writeData(ExternalizePersister.java:58) | at org.jboss.serial.objectmetamodel.ObjectDescriptorFactory.describeObject(ObjectDescriptorFactory.java:276) | at org.jboss.serial.objectmetamodel.DataContainer$DataContainerDirectOutput.writeObject(DataContainer.java:206) | at org.jboss.serial.io.JBossObjectOutputStream.writeObjectOverride(JBossObjectOutputStream.java:181) | Caused by: java.lang.NullPointerException | at javax.faces.component.UIComponentBase.saveAttachedState(UIComponentBase.java:1339) | at javax.faces.component.UIComponentBase.saveBindingsState(UIComponentBase.java:1447) | at javax.faces.component.UIComponentBase.saveState(UIComponentBase.java:1238) | at javax.faces.component.UIData.saveState(UIData.java:530) | at javax.faces.component.html.HtmlDataTable.saveState(HtmlDataTable.java:883) | at javax.faces.component.UIComponentBase$AttributesMap.writeObject(UIComponentBase.java:1760) | 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.jboss.serial.persister.RegularObjectPersister.writeSlotWithMethod(RegularObjectPersister.java:120) | at org.jboss.serial.persister.RegularObjectPersister.defaultWrite(RegularObjectPersister.java:86) | at org.jboss.serial.persister.RegularObjectPersister.writeData(RegularObjectPersister.java:62) | at org.jboss.serial.objectmetamodel.ObjectDescriptorFactory.describeObject(ObjectDescriptorFactory.java:276) | at org.jboss.serial.objectmetamodel.DataContainer$DataContainerDirectOutput.writeObject(DataContainer.java:206) | at org.jboss.serial.persister.RegularObjectPersister.writeSlotWithFields(RegularObjectPersister.java:182) | at org.jboss.serial.persister.RegularObjectPersister.defaultWrite(RegularObjectPersister.java:90) | at org.jboss.serial.persister.RegularObjectPersister.writeData(RegularObjectPersister.java:62) | at org.jboss.serial.objectmetamodel.ObjectDescriptorFactory.describeObject(ObjectDescriptorFactory.java:276) | at org.jboss.serial.objectmetamodel.DataContainer$DataContainerDirectOutput.writeObject(DataContainer.java:206) | at org.jboss.serial.persister.RegularObjectPersister.writeSlotWithFields(RegularObjectPersister.java:182) | at org.jboss.serial.persister.RegularObjectPersister.defaultWrite(RegularObjectPersister.java:90) | at org.jboss.serial.persister.RegularObjectPersister.writeData(RegularObjectPersister.java:62) | at org.jboss.serial.objectmetamodel.ObjectDescriptorFactory.describeObject(ObjectDescriptorFactory.java:276) | at org.jboss.serial.objectmetamodel.DataContainer$DataContainerDirectOutput.writeObject(DataContainer.java:206) | at org.jboss.serial.persister.ArrayPersister.saveObjectArray(ArrayPersister.java:110) | at org.jboss.serial.persister.ArrayPersister.writeData(ArrayPersister.java:101) | at org.jboss.serial.objectmetamodel.ObjectDescriptorFactory.describeObject(ObjectDescriptorFactory.java:276) | at org.jboss.serial.objectmetamodel.DataContainer$DataContainerDirectOutput.writeObject(DataContainer.java:206) | at org.jboss.serial.io.JBossObjectOutputStream.writeObjectOverride(JBossObjectOutputStream.java:181) | at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:322) | at org.jboss.serial.io.MarshalledObject.<init>(MarshalledObject.java:51) | at org.jboss.ejb3.stateful.StatefulBeanContext.writeExternal(StatefulBeanContext.java:842) | at org.jboss.serial.persister.ExternalizePersister.writeData(ExternalizePersister.java:58) | at org.jboss.serial.objectmetamodel.ObjectDescriptorFactory.describeObject(ObjectDescriptorFactory.java:276) | at org.jboss.serial.objectmetamodel.DataContainer$DataContainerDirectOutput.writeObject(DataContainer.java:206) | at org.jboss.serial.io.JBossObjectOutputStream.writeObjectOverride(JBossObjectOutputStream.java:181) | at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:322) | at org.jboss.ejb3.cache.simple.StatefulSessionFilePersistenceManager.passivateSession(StatefulSessionFilePersistenceManager.java:390) | at org.jboss.ejb3.cache.simple.SimpleStatefulCache.passivate(SimpleStatefulCache.java:301) | at org.jboss.ejb3.cache.simple.SimpleStatefulCache$SessionTimeoutTask.run(SimpleStatefulCache.java:209) | View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4124927#... 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