Message Title

We’ve encountered a very unusual exception which seemed to be related to a specific entity. The exception started with the deployment of a specific release and was gone after the following release was deployed. None of the changes in both releases seemed to correlate to the exception and/or the entity. All other functionalities of the application were working as expected, including lots of Hibernate-related logic.
We were not able to reproduce this, but looking at AbstractRowReader it seems that the NullPointerException can only occur if it has already been initialized the wrong way with a null value in entityReferenceInitializers.
Caused by: java.lang.NullPointerException: Cannot invoke "org.hibernate.loader.plan.exec.process.spi.EntityReferenceInitializer.getEntityReference()" because "entityReferenceInitializer" is null
	at org.hibernate.loader.plan.exec.process.internal.AbstractRowReader.resolveEntityKey(AbstractRowReader.java:104)
	at org.hibernate.loader.plan.exec.process.internal.AbstractRowReader.resolveEntityKey(AbstractRowReader.java:120)
	at org.hibernate.loader.plan.exec.process.internal.AbstractRowReader.resolveEntityKey(AbstractRowReader.java:108)
	at org.hibernate.loader.plan.exec.process.internal.AbstractRowReader.readRow(AbstractRowReader.java:71)
	at org.hibernate.loader.plan.exec.internal.EntityLoadQueryDetails$EntityLoaderRowReader.readRow(EntityLoadQueryDetails.java:288)
	at org.hibernate.loader.plan.exec.process.internal.ResultSetProcessorImpl.extractRows(ResultSetProcessorImpl.java:157)
	at org.hibernate.loader.plan.exec.process.internal.ResultSetProcessorImpl.extractResults(ResultSetProcessorImpl.java:94)
	at org.hibernate.loader.plan.exec.internal.AbstractLoadPlanBasedLoader.executeLoad(AbstractLoadPlanBasedLoader.java:105)
	at org.hibernate.loader.entity.plan.AbstractLoadPlanBasedEntityLoader.load(AbstractLoadPlanBasedEntityLoader.java:285)
	at org.hibernate.persister.entity.AbstractEntityPersister.doLoad(AbstractEntityPersister.java:4550)
	at org.hibernate.persister.entity.AbstractEntityPersister.load(AbstractEntityPersister.java:4540)
	at org.hibernate.event.internal.DefaultLoadEventListener.loadFromDatasource(DefaultLoadEventListener.java:571)
	at org.hibernate.event.internal.DefaultLoadEventListener.doLoad(DefaultLoadEventListener.java:539)
	at org.hibernate.event.internal.DefaultLoadEventListener.load(DefaultLoadEventListener.java:208)
	at org.hibernate.event.internal.DefaultLoadEventListener.proxyOrLoad(DefaultLoadEventListener.java:327)
	at org.hibernate.event.internal.DefaultLoadEventListener.doOnLoad(DefaultLoadEventListener.java:108)
	at org.hibernate.event.internal.DefaultLoadEventListener.onLoad(DefaultLoadEventListener.java:74)
	at org.hibernate.event.service.internal.EventListenerGroupImpl.fireEventOnEachListener(EventListenerGroupImpl.java:118)
	at org.hibernate.internal.SessionImpl.fireLoadNoChecks(SessionImpl.java:1231)
	at org.hibernate.internal.SessionImpl.internalLoad(SessionImpl.java:1096)
	at org.hibernate.type.EntityType.resolveIdentifier(EntityType.java:706)
	at org.hibernate.type.EntityType.resolve(EntityType.java:465)
	at org.hibernate.type.ManyToOneType.resolve(ManyToOneType.java:265)
	at org.hibernate.type.EntityType.resolve(EntityType.java:458)
	at org.hibernate.type.ComponentType.resolve(ComponentType.java:695)
	at org.hibernate.loader.Loader.extractKeysFromResultSet(Loader.java:881)
	at org.hibernate.loader.Loader.getRowFromResultSet(Loader.java:735)
	at org.hibernate.loader.Loader.getRowsFromResultSet(Loader.java:1047)
	at org.hibernate.loader.Loader.processResultSet(Loader.java:998)
	at org.hibernate.loader.Loader.doQuery(Loader.java:967)
	at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:357)
	at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:327)
	at org.hibernate.loader.Loader.loadEntity(Loader.java:2440)
	at org.hibernate.loader.entity.AbstractEntityLoader.load(AbstractEntityLoader.java:77)
	at org.hibernate.loader.entity.AbstractEntityLoader.load(AbstractEntityLoader.java:66)
	at org.hibernate.persister.entity.AbstractEntityPersister.loadByUniqueKey(AbstractEntityPersister.java:2486)
	at org.hibernate.type.EntityType.loadByUniqueKey(EntityType.java:763)
	at org.hibernate.type.EntityType.resolve(EntityType.java:468)
	at org.hibernate.engine.internal.TwoPhaseLoad$EntityResolver.lambda$static$0(TwoPhaseLoad.java:576)
	at org.hibernate.engine.internal.TwoPhaseLoad.initializeEntityEntryLoadedState(TwoPhaseLoad.java:221)
	at org.hibernate.engine.internal.TwoPhaseLoad.initializeEntity(TwoPhaseLoad.java:155)
	at org.hibernate.engine.internal.TwoPhaseLoad.initializeEntity(TwoPhaseLoad.java:126)
	at org.hibernate.loader.Loader.initializeEntitiesAndCollections(Loader.java:1201)
	at org.hibernate.loader.Loader.processResultSet(Loader.java:1009)
	at org.hibernate.loader.Loader.doQuery(Loader.java:967)
	at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:357)
	at org.hibernate.loader.Loader.doList(Loader.java:2868)
	at org.hibernate.loader.Loader.doList(Loader.java:2850)
	at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2682)
	at org.hibernate.loader.Loader.list(Loader.java:2677)
	at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:540)
	at org.hibernate.hql.internal.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:400)
	at org.hibernate.engine.query.spi.HQLQueryPlan.performList(HQLQueryPlan.java:218)
	at org.hibernate.internal.SessionImpl.list(SessionImpl.java:1459)
	at org.hibernate.query.internal.AbstractProducedQuery.doList(AbstractProducedQuery.java:1649)
	at org.hibernate.query.internal.AbstractProducedQuery.list(AbstractProducedQuery.java:1617)
	at org.hibernate.query.Query.getResultList(Query.java:165)
	at org.hibernate.query.criteria.internal.compile.CriteriaQueryTypeQueryAdapter.getResultList(CriteriaQueryTypeQueryAdapter.java:76)
	at org.springframework.data.jpa.repository.query.JpaQueryExecution$CollectionExecution.doExecute(JpaQueryExecution.java:128)
	at org.springframework.data.jpa.repository.query.JpaQueryExecution.execute(JpaQueryExecution.java:90)
	at org.springframework.data.jpa.repository.query.AbstractJpaQuery.doExecute(AbstractJpaQuery.java:156)
	at org.springframework.data.jpa.repository.query.AbstractJpaQuery.execute(AbstractJpaQuery.java:144)
	at org.springframework.data.repository.core.support.RepositoryMethodInvoker.doInvoke(RepositoryMethodInvoker.java:137)
	at org.springframework.data.repository.core.support.RepositoryMethodInvoker.invoke(RepositoryMethodInvoker.java:121)
	at org.springframework.data.repository.core.support.QueryExecutorMethodInterceptor.doInvoke(QueryExecutorMethodInterceptor.java:160)
	at org.springframework.data.repository.core.support.QueryExecutorMethodInterceptor.invoke(QueryExecutorMethodInterceptor.java:139)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
	at org.springframework.data.projection.DefaultMethodInvokingMethodInterceptor.invoke(DefaultMethodInvokingMethodInterceptor.java:81)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
	at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:123)
	at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:388)
	at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:119)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
	at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:137)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
	at org.springframework.data.jpa.repository.support.CrudMethodMetadataPostProcessor$CrudMethodMetadataPopulatingMethodInterceptor.invoke(CrudMethodMetadataPostProcessor.java:145)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
	at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:97)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
	at datadog.trace.instrumentation.springdata.RepositoryInterceptor.invoke(RepositoryInterceptor.java:43)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
	at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:220)
	at jdk.proxy5/jdk.proxy5.$Proxy323.findAllBy...InAnd...In(Unknown Source)