Index Auto update with Lazy collections not working

I am getting following error
Hibernate search index auto update is not working with lazy collections

org.springframework.orm.hibernate5.HibernateSystemException: Error while indexing in Hibernate Search (before transaction completion); nested exception is org.hibernate.HibernateException: Error while indexing in Hibernate Search (before transaction completion)
	at org.springframework.orm.hibernate5.SessionFactoryUtils.convertHibernateAccessException(SessionFactoryUtils.java:302)
	at org.springframework.orm.hibernate5.HibernateTransactionManager.convertHibernateAccessException(HibernateTransactionManager.java:801)
	at org.springframework.orm.hibernate5.HibernateTransactionManager.doCommit(HibernateTransactionManager.java:633)
	at org.springframework.transaction.support.AbstractPlatformTransactionManager.processCommit(AbstractPlatformTransactionManager.java:746)
	at org.springframework.transaction.support.AbstractPlatformTransactionManager.commit(AbstractPlatformTransactionManager.java:714)
	at org.springframework.transaction.interceptor.TransactionAspectSupport.commitTransactionAfterReturning(TransactionAspectSupport.java:533)
	at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:304)
	at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:98)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
	at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212)
	at com.sun.proxy.$Proxy92.addNewJobPost(Unknown Source)
	at com.cdac.internship.service.CompanyServiceImpl.addNewJobPost(CompanyServiceImpl.java:33)
	at com.cdac.internship.controller.CompanyController.savejob(CompanyController.java:190)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:189)
	at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138)
	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102)
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:895)
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:800)
	at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1038)
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:942)
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1005)
	at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:908)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:661)
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:882)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at com.cdac.internship.filters.XSSFilter.doFilter(XSSFilter.java:31)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:316)
	at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:126)
	at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:90)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
	at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:114)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
	at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:122)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
	at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:111)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
	at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:168)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
	at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:48)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
	at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:205)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
	at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:120)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
	at org.springframework.security.web.csrf.CsrfFilter.doFilterInternal(CsrfFilter.java:120)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
	at org.springframework.security.web.header.HeaderWriterFilter.doFilterInternal(HeaderWriterFilter.java:64)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
	at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:91)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
	at org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:53)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
	at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:213)
	at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:176)
	at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:357)
	at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:270)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:478)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:80)
	at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:624)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)
	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:799)
	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868)
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1455)
	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
	at java.lang.Thread.run(Thread.java:748)
Caused by: org.hibernate.HibernateException: Error while indexing in Hibernate Search (before transaction completion)
	at org.hibernate.search.event.impl.EventSourceTransactionContext$DelegateToSynchronizationOnBeforeTx.doBeforeTransactionCompletion(EventSourceTransactionContext.java:173)
	at org.hibernate.engine.spi.ActionQueue$BeforeTransactionCompletionProcessQueue.beforeTransactionCompletion(ActionQueue.java:954)
	at org.hibernate.engine.spi.ActionQueue.beforeTransactionCompletion(ActionQueue.java:525)
	at org.hibernate.internal.SessionImpl.beforeTransactionCompletion(SessionImpl.java:2493)
	at org.hibernate.engine.jdbc.internal.JdbcCoordinatorImpl.beforeTransactionCompletion(JdbcCoordinatorImpl.java:473)
	at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl.beforeCompletionCallback(JdbcResourceLocalTransactionCoordinatorImpl.java:178)
	at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl.access$300(JdbcResourceLocalTransactionCoordinatorImpl.java:39)
	at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl$TransactionDriverControlImpl.commit(JdbcResourceLocalTransactionCoordinatorImpl.java:271)
	at org.hibernate.engine.transaction.internal.TransactionImpl.commit(TransactionImpl.java:104)
	at org.springframework.orm.hibernate5.HibernateTransactionManager.doCommit(HibernateTransactionManager.java:625)
	... 87 more
Caused by: java.lang.IllegalStateException: Could not get property value
	at org.hibernate.search.util.impl.ReflectionHelper.getMemberValue(ReflectionHelper.java:94)
	at org.hibernate.search.engine.spi.DocumentBuilderIndexedEntity.buildDocumentFieldsForProperties(DocumentBuilderIndexedEntity.java:641)
	at org.hibernate.search.engine.spi.DocumentBuilderIndexedEntity.buildDocumentFields(DocumentBuilderIndexedEntity.java:466)
	at org.hibernate.search.engine.spi.DocumentBuilderIndexedEntity.buildDocumentFieldsForEmbeddedObjects(DocumentBuilderIndexedEntity.java:555)
	at org.hibernate.search.engine.spi.DocumentBuilderIndexedEntity.buildDocumentFields(DocumentBuilderIndexedEntity.java:482)
	at org.hibernate.search.engine.spi.DocumentBuilderIndexedEntity.getDocument(DocumentBuilderIndexedEntity.java:402)
	at org.hibernate.search.engine.spi.DocumentBuilderIndexedEntity.createAddWork(DocumentBuilderIndexedEntity.java:299)
	at org.hibernate.search.engine.spi.DocumentBuilderIndexedEntity.addWorkToQueue(DocumentBuilderIndexedEntity.java:241)
	at org.hibernate.search.engine.impl.WorkPlan$PerEntityWork.enqueueLuceneWork(WorkPlan.java:560)
	at org.hibernate.search.engine.impl.WorkPlan$PerClassWork.enqueueLuceneWork(WorkPlan.java:322)
	at org.hibernate.search.engine.impl.WorkPlan.getPlannedLuceneWork(WorkPlan.java:188)
	at org.hibernate.search.backend.impl.WorkQueue.prepareWorkPlan(WorkQueue.java:115)
	at org.hibernate.search.backend.impl.BatchedQueueingProcessor.prepareWorks(BatchedQueueingProcessor.java:55)
	at org.hibernate.search.backend.impl.PostTransactionWorkQueueSynchronization.beforeCompletion(PostTransactionWorkQueueSynchronization.java:67)
	at org.hibernate.search.event.impl.EventSourceTransactionContext$DelegateToSynchronizationOnBeforeTx.doBeforeTransactionCompletion(EventSourceTransactionContext.java:170)
	... 96 more
Caused by: java.lang.IllegalArgumentException: Invoking skillName on a  null object
	at org.hibernate.annotations.common.reflection.java.JavaXProperty.invoke(JavaXProperty.java:105)
	at org.hibernate.annotations.common.reflection.java.JavaXProperty.invoke(JavaXProperty.java:120)
	at org.hibernate.search.util.impl.ReflectionHelper.getMemberValue(ReflectionHelper.java:91)
	... 110 more
Caused by: java.lang.NullPointerException
	at sun.reflect.UnsafeFieldAccessorImpl.ensureObj(UnsafeFieldAccessorImpl.java:57)
	at sun.reflect.UnsafeObjectFieldAccessorImpl.get(UnsafeObjectFieldAccessorImpl.java:36)
	at java.lang.reflect.Field.get(Field.java:393)
	at org.hibernate.annotations.common.reflection.java.JavaXProperty.invoke(JavaXProperty.java:101)
	... 112 more

Following is my Pojo calss

@Entity
@Indexed
@Table(name = "jobpost")
public class JobPost  {

	@Id
	@GeneratedValue(strategy = GenerationType.IDENTITY)
	@Column(name = "jobid", unique = true, nullable = false)
	private long jobid;

	@Field(index = Index.YES, analyze = Analyze.YES, store = Store.NO)
	@Column(name = "jobtitle", length = 50)
	private String jobtitle;
 .
.
.
@IndexedEmbedded
	@ManyToMany
	@Cascade({ CascadeType.SAVE_UPDATE, CascadeType.DELETE, CascadeType.ALL })
	@JoinTable(name = "jobpost_skills", joinColumns = { @JoinColumn(name = "jobid") }, inverseJoinColumns = {
			@JoinColumn(name = "id") })
	private Set<Skills> skillset = new HashSet<Skills>();
	

}

Skills.java is as fallows

@Entity
@Table(name = "skills")
public class Skills {

	@Id
	@GeneratedValue(strategy = GenerationType.IDENTITY)
	@Column(name = "id", unique = true, nullable = false)
	private long id;

	@Field
	@Column(name = "skillname")
	private String skillName;

	@ManyToMany(mappedBy = "skillset", targetEntity = JobPost.class)
	private Set<JobPost> jobpost = new HashSet<JobPost>();
}

Hibernate properties are

<beans:prop key="hibernate.dialect">org.hibernate.dialect.PostgreSQLDialect
				</beans:prop>
				<beans:prop key="hibernate.show_sql">false</beans:prop>
				<beans:prop key="hibernate.hbm2ddl.auto">update</beans:prop>
				<beans:prop key="hibernate.enable_lazy_load_no_trans">true</beans:prop>
<beans:prop key="hibernate.search.default.directory_provider">filesystem</beans:prop> 
				<beans:prop key="hibernate.search.default.indexBase">/var/index</beans:prop>

and for transaction managemant am using this

	<tx:annotation-driven
		transaction-manager="transactionManager" />


	<beans:bean id="transactionManager"
		class="org.springframework.orm.hibernate5.HibernateTransactionManager">
		<beans:property name="sessionFactory"
			ref="hibernate5LocalSessionFactory" />
	</beans:bean>

My spring version is 5.1.4.RELEASE
and hibernate version is

<dependency>
			<groupId>org.hibernate</groupId>
			<artifactId>hibernate-search-orm</artifactId>
			<version>5.11.0.Final</version>
		</dependency>

when am going to save Jobpost in db am using @Transactional on dao implementation methods

Before that am using hibernate fetchType.Eager at that time every thing is working fine
but due to performance issue i have removed Eager fetching and Lazy fetch default provided by hibernate is used

but due to this am getting above error
Please help me to solve this problem
Thanks in advance