PropertyAccessException in Private Messages

013-10-21 17:13:04 [WARN ][http-8080-6     ][anonymous-6D74][                 org.jtalks.jcommune] - Handler execution resulted in exception
org.hibernate.PropertyAccessException: Exception occurred inside getter of org.jtalks.common.model.entity.Entity.id
        at org.hibernate.property.BasicPropertyAccessor$BasicGetter.get(BasicPropertyAccessor.java:175)
        at org.hibernate.tuple.entity.AbstractEntityTuplizer.getIdentifier(AbstractEntityTuplizer.java:227)
        at org.hibernate.persister.entity.AbstractEntityPersister.getIdentifier(AbstractEntityPersister.java:3875)
        at org.hibernate.persister.entity.AbstractEntityPersister.isTransient(AbstractEntityPersister.java:3583)
        at org.hibernate.engine.ForeignKeys.isTransient(ForeignKeys.java:203)
        at org.hibernate.engine.ForeignKeys.getEntityIdentifierIfNotUnsaved(ForeignKeys.java:242)
        at org.hibernate.type.EntityType.getIdentifier(EntityType.java:456)
        at org.hibernate.type.ManyToOneType.nullSafeSet(ManyToOneType.java:130)
        at org.hibernate.param.NamedParameterSpecification.bind(NamedParameterSpecification.java:67)
        at org.hibernate.loader.hql.QueryLoader.bindParameterValues(QueryLoader.java:571)
        at org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1716)
        at org.hibernate.loader.Loader.doQuery(Loader.java:801)
        at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:274)
        at org.hibernate.loader.Loader.doList(Loader.java:2533)
        at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2276)
        at org.hibernate.loader.Loader.list(Loader.java:2271)
        at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:452)
        at org.hibernate.hql.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:363)
        at org.hibernate.engine.query.HQLQueryPlan.performList(HQLQueryPlan.java:196)
        at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1268)
        at org.hibernate.impl.QueryImpl.list(QueryImpl.java:102)
        at org.hibernate.impl.AbstractQueryImpl.uniqueResult(AbstractQueryImpl.java:890)
        at org.jtalks.jcommune.model.dao.hibernate.PrivateMessageHibernateDao.getOutboxMessageCount(PrivateMessageHibernateDao.java:82)
        at org.jtalks.jcommune.model.dao.hibernate.PrivateMessageHibernateDao.getAllFromUser(PrivateMessageHibernateDao.java:59)
        at sun.reflect.GeneratedMethodAccessor496.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:606)
        at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:317)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:183)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)
        at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:91)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)