Strange error with Lucene indexing

[mvsjober]

2017-06-15 15:24:47.828 ERROR 26450 --- [pool-2-thread-1] o.s.s.s.TaskUtils$LoggingErrorHandler    : Unexpected error occurred in scheduled task.

org.springframework.dao.InvalidDataAccessApiUsageException: The given id must not be null!; nested exception is java.lang.IllegalArgumentException: The given id must not be null!
	at org.springframework.orm.jpa.EntityManagerFactoryUtils.convertJpaAccessExceptionIfPossible(EntityManagerFactoryUtils.java:384) ~[spring-orm-4.2.5.RELEASE.jar!/:4.2.5.RELEASE]
	at org.springframework.orm.jpa.vendor.HibernateJpaDialect.translateExceptionIfPossible(HibernateJpaDialect.java:227) ~[spring-orm-4.2.5.RELEASE.jar!/:4.2.5.RELEASE]
	at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.translateExceptionIfPossible(AbstractEntityManagerFactoryBean.java:436) ~[spring-orm-4.2.5.RELEASE.jar!/:4.2.5.RELEASE]
	at org.springframework.dao.support.ChainedPersistenceExceptionTranslator.translateExceptionIfPossible(ChainedPersistenceExceptionTranslator.java:59) ~[spring-tx-4.2.5.RELEASE.jar!/:4.2.5.RELEASE]
	at org.springframework.dao.support.DataAccessUtils.translateIfNecessary(DataAccessUtils.java:213) ~[spring-tx-4.2.5.RELEASE.jar!/:4.2.5.RELEASE]
	at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:147) ~[spring-tx-4.2.5.RELEASE.jar!/:4.2.5.RELEASE]
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.2.5.RELEASE.jar!/:4.2.5.RELEASE]
	at org.springframework.data.jpa.repository.support.CrudMethodMetadataPostProcessor$CrudMethodMetadataPopulatingMethodInterceptor.invoke(CrudMethodMetadataPostProcessor.java:131) ~[spring-data-jpa-1.9.4.RELEASE.jar!/:na]
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.2.5.RELEASE.jar!/:4.2.5.RELEASE]
	at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92) ~[spring-aop-4.2.5.RELEASE.jar!/:4.2.5.RELEASE]
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.2.5.RELEASE.jar!/:4.2.5.RELEASE]
	at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:208) ~[spring-aop-4.2.5.RELEASE.jar!/:4.2.5.RELEASE]
	at com.sun.proxy.$Proxy110.findOne(Unknown Source) ~[na:na]
	at fi.hiit.dime.database.DiMeDAO.findById(DiMeDAO.java:74) ~[dime-server.jar!/:na]
	at fi.hiit.dime.database.DiMeDAO.getNotIndexed(DiMeDAO.java:196) ~[dime-server.jar!/:na]
	at fi.hiit.dime.database.DiMeDAO$$FastClassBySpringCGLIB$$1b409e3c.invoke(<generated>) ~[dime-server.jar!/:na]
	at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204) ~[spring-core-4.2.5.RELEASE.jar!/:4.2.5.RELEASE]
	at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:651) ~[spring-aop-4.2.5.RELEASE.jar!/:4.2.5.RELEASE]
	at fi.hiit.dime.database.InformationElementDAO$$EnhancerBySpringCGLIB$$27fdefda.getNotIndexed(<generated>) ~[dime-server.jar!/:na]
	at fi.hiit.dime.search.SearchIndex.updateIndex(SearchIndex.java:383) ~[dime-server.jar!/:na]
	at fi.hiit.dime.ApiController.updateSearchIndex(ApiController.java:431) ~[dime-server.jar!/:na]
	at fi.hiit.dime.ApiController$$FastClassBySpringCGLIB$$312724fc.invoke(<generated>) ~[dime-server.jar!/:na]
	at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204) ~[spring-core-4.2.5.RELEASE.jar!/:4.2.5.RELEASE]
	at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:720) ~[spring-aop-4.2.5.RELEASE.jar!/:4.2.5.RELEASE]
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157) ~[spring-aop-4.2.5.RELEASE.jar!/:4.2.5.RELEASE]
	at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99) ~[spring-tx-4.2.5.RELEASE.jar!/:4.2.5.RELEASE]
	at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:281) ~[spring-tx-4.2.5.RELEASE.jar!/:4.2.5.RELEASE]
	at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96) ~[spring-tx-4.2.5.RELEASE.jar!/:4.2.5.RELEASE]
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.2.5.RELEASE.jar!/:4.2.5.RELEASE]
	at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:655) ~[spring-aop-4.2.5.RELEASE.jar!/:4.2.5.RELEASE]
	at fi.hiit.dime.ApiController$$EnhancerBySpringCGLIB$$e7cf7f8d.updateSearchIndex(<generated>) ~[dime-server.jar!/:na]
	at sun.reflect.GeneratedMethodAccessor310.invoke(Unknown Source) ~[na:na]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_131]
	at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_131]
	at org.springframework.scheduling.support.ScheduledMethodRunnable.run(ScheduledMethodRunnable.java:65) ~[spring-context-4.2.5.RELEASE.jar!/:4.2.5.RELEASE]
	at org.springframework.scheduling.support.DelegatingErrorHandlingRunnable.run(DelegatingErrorHandlingRunnable.java:54) ~[spring-context-4.2.5.RELEASE.jar!/:4.2.5.RELEASE]
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [na:1.8.0_131]
	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308) [na:1.8.0_131]
	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180) [na:1.8.0_131]
	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294) [na:1.8.0_131]
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_131]
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_131]
	at java.lang.Thread.run(Thread.java:748) [na:1.8.0_131]
Caused by: java.lang.IllegalArgumentException: The given id must not be null!
	at org.springframework.util.Assert.notNull(Assert.java:115) ~[spring-core-4.2.5.RELEASE.jar!/:4.2.5.RELEASE]
	at org.springframework.data.jpa.repository.support.SimpleJpaRepository.findOne(SimpleJpaRepository.java:223) ~[spring-data-jpa-1.9.4.RELEASE.jar!/:na]
	at sun.reflect.GeneratedMethodAccessor302.invoke(Unknown Source) ~[na:na]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_131]
	at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_131]
	at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.executeMethodOn(RepositoryFactorySupport.java:483) ~[spring-data-commons-1.11.4.RELEASE.jar!/:na]
	at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:468) ~[spring-data-commons-1.11.4.RELEASE.jar!/:na]
	at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:440) ~[spring-data-commons-1.11.4.RELEASE.jar!/:na]
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.2.5.RELEASE.jar!/:4.2.5.RELEASE]
	at org.springframework.data.projection.DefaultMethodInvokingMethodInterceptor.invoke(DefaultMethodInvokingMethodInterceptor.java:61) ~[spring-data-commons-1.11.4.RELEASE.jar!/:na]
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.2.5.RELEASE.jar!/:4.2.5.RELEASE]
	at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99) ~[spring-tx-4.2.5.RELEASE.jar!/:4.2.5.RELEASE]
	at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:281) ~[spring-tx-4.2.5.RELEASE.jar!/:4.2.5.RELEASE]
	at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96) ~[spring-tx-4.2.5.RELEASE.jar!/:4.2.5.RELEASE]
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.2.5.RELEASE.jar!/:4.2.5.RELEASE]
	at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:136) ~[spring-tx-4.2.5.RELEASE.jar!/:4.2.5.RELEASE]
	... 37 common frames omitted