inception: NullPointerException during export in WebAnno format

Describe the bug I got a NullPointerException error when exporting one or more files having one relation between entities.

To Reproduce Unfortunately I cannot reproduce the problem from scratch. I set up my annotation task with 7 layers and a lot of rules, and when I try to export in WebAnno format a document containing a relation between spans I got an error. The problem does not appear when exporting in other formats nor exporting in WebAnno when the document does not contain relations (only spans).

Screenshots

Please complete the following information:

• Version and build ID: 24.3
• OS: Linux (Ubuntu Server)
• Browser: Chrome

Additional context The error:

org.apache.uima.analysis_engine.AnalysisEngineProcessException: Annotator processing failed.    
	at org.apache.uima.analysis_engine.impl.PrimitiveAnalysisEngine_impl.callAnalysisComponentProcess(PrimitiveAnalysisEngine_impl.java:415) ~[uimaj-core-3.3.0.jar!/:3.3.0]
	at org.apache.uima.analysis_engine.impl.PrimitiveAnalysisEngine_impl.processAndOutputNewCASes(PrimitiveAnalysisEngine_impl.java:299) ~[uimaj-core-3.3.0.jar!/:3.3.0]
	at org.apache.uima.analysis_engine.impl.AnalysisEngineImplBase.process(AnalysisEngineImplBase.java:295) ~[uimaj-core-3.3.0.jar!/:3.3.0]
	at de.tudarmstadt.ukp.clarin.webanno.api.format.FormatSupport.write(FormatSupport.java:163) ~[inception-api-formats-24.3.jar!/:?]
	at de.tudarmstadt.ukp.inception.export.DocumentImportExportServiceImpl.exportCasToFile(DocumentImportExportServiceImpl.java:490) ~[inception-export-24.3.jar!/:?]
	at de.tudarmstadt.ukp.inception.export.DocumentImportExportServiceImpl.exportAnnotationDocument(DocumentImportExportServiceImpl.java:237) ~[inception-export-24.3.jar!/:?]
	at de.tudarmstadt.ukp.inception.export.DocumentImportExportServiceImpl.exportAnnotationDocument(DocumentImportExportServiceImpl.java:204) ~[inception-export-24.3.jar!/:?]
	at de.tudarmstadt.ukp.inception.export.DocumentImportExportServiceImpl$$FastClassBySpringCGLIB$$6bf689d0.invoke(<generated>) ~[inception-export-24.3.jar!/:?]
	at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218) ~[spring-core-5.3.22.jar!/:5.3.22]
	at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:793) ~[spring-aop-5.3.22.jar!/:5.3.22]
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163) ~[spring-aop-5.3.22.jar!/:5.3.22]
	at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:763) ~[spring-aop-5.3.22.jar!/:5.3.22]
	at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:123) ~[spring-tx-5.3.22.jar!/:5.3.22]
	at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:388) ~[spring-tx-5.3.22.jar!/:5.3.22]
	at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:119) ~[spring-tx-5.3.22.jar!/:5.3.22]
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.3.22.jar!/:5.3.22]
	at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:763) ~[spring-aop-5.3.22.jar!/:5.3.22]
	at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:708) ~[spring-aop-5.3.22.jar!/:5.3.22]
	at de.tudarmstadt.ukp.inception.export.DocumentImportExportServiceImpl$$EnhancerBySpringCGLIB$$e396129c.exportAnnotationDocument(<generated>) ~[inception-export-24.3.jar!/:?]
	at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:?]
	at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:?]
	at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:?]
	at java.lang.reflect.Method.invoke(Method.java:566) ~[?:?]
	at org.apache.wicket.proxy.jdk.JdkProxyFactory$JdkHandler.invoke(JdkProxyFactory.java:172) ~[wicket-ioc-9.11.0.jar!/:9.11.0]
	at com.sun.proxy.$Proxy270.exportAnnotationDocument(Unknown Source) ~[?:?]
	at de.tudarmstadt.ukp.clarin.webanno.api.annotation.actionbar.export.ExportDocumentDialogContent.export(ExportDocumentDialogContent.java:95) ~[inception-api-annotation-24.3.jar!/:?]
	at org.apache.wicket.model.LoadableDetachableModel$1.load(LoadableDetachableModel.java:216) ~[wicket-core-9.11.0.jar!/:9.11.0]
	at org.apache.wicket.model.LoadableDetachableModel.getObject(LoadableDetachableModel.java:128) ~[wicket-core-9.11.0.jar!/:9.11.0]
	at org.apache.wicket.Component.getDefaultModelObject(Component.java:1592) ~[wicket-core-9.11.0.jar!/:9.11.0]
	at org.apache.wicket.IGenericComponent.getModelObject(IGenericComponent.java:70) ~[wicket-core-9.11.0.jar!/:9.11.0]
	at de.tudarmstadt.ukp.clarin.webanno.support.wicket.AjaxDownloadLink$1.onRequest(AjaxDownloadLink.java:86) ~[inception-support-24.3.jar!/:?]
	at org.apache.wicket.core.request.handler.ListenerRequestHandler.internalInvoke(ListenerRequestHandler.java:306) ~[wicket-core-9.11.0.jar!/:9.11.0]
	at org.apache.wicket.core.request.handler.ListenerRequestHandler.invoke(ListenerRequestHandler.java:280) ~[wicket-core-9.11.0.jar!/:9.11.0]
	at org.apache.wicket.core.request.handler.ListenerRequestHandler.invokeListener(ListenerRequestHandler.java:222) ~[wicket-core-9.11.0.jar!/:9.11.0]
	at org.apache.wicket.core.request.handler.ListenerRequestHandler.respond(ListenerRequestHandler.java:208) ~[wicket-core-9.11.0.jar!/:9.11.0]
	at org.apache.wicket.request.cycle.RequestCycle$HandlerExecutor.respond(RequestCycle.java:910) ~[wicket-core-9.11.0.jar!/:9.11.0]
	at org.apache.wicket.request.RequestHandlerExecutor.execute(RequestHandlerExecutor.java:63) ~[wicket-request-9.11.0.jar!/:9.11.0]
	at org.apache.wicket.request.cycle.RequestCycle.execute(RequestCycle.java:294) ~[wicket-core-9.11.0.jar!/:9.11.0]
	at org.apache.wicket.request.cycle.RequestCycle.processRequest(RequestCycle.java:255) ~[wicket-core-9.11.0.jar!/:9.11.0]
	at org.apache.wicket.protocol.http.WicketFilter.processRequestCycle(WicketFilter.java:277) ~[wicket-core-9.11.0.jar!/:9.11.0]
	at org.apache.wicket.protocol.http.WicketFilter.processRequest(WicketFilter.java:208) ~[wicket-core-9.11.0.jar!/:9.11.0]
	at org.apache.wicket.protocol.http.WicketFilter.doFilter(WicketFilter.java:307) ~[wicket-core-9.11.0.jar!/:9.11.0]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.65.jar!/:?]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.65.jar!/:?]
	at org.springframework.orm.jpa.support.OpenEntityManagerInViewFilter.doFilterInternal(OpenEntityManagerInViewFilter.java:186) ~[spring-orm-5.3.22.jar!/:5.3.22]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.22.jar!/:5.3.22]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.65.jar!/:?]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.65.jar!/:?]
	at de.tudarmstadt.ukp.clarin.webanno.support.logging.LoggingFilter.doFilter(LoggingFilter.java:58) ~[inception-support-24.3.jar!/:?]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.65.jar!/:?]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.65.jar!/:?]
	at de.tudarmstadt.ukp.inception.app.config.InceptionServletContextInitializer$1.doFilter(InceptionServletContextInitializer.java:96) ~[classes!/:?]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.65.jar!/:?]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.65.jar!/:?]
	at de.tudarmstadt.ukp.inception.annotation.storage.OpenCasStorageSessionForRequestFilter.doFilter(OpenCasStorageSessionForRequestFilter.java:50) ~[inception-annotation-storage-24.3.jar!/:?]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.65.jar!/:?]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.65.jar!/:?]
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:337) ~[spring-security-web-5.7.3.jar!/:5.7.3]
	at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:115) ~[spring-security-web-5.7.3.jar!/:5.7.3]
	at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:81) ~[spring-security-web-5.7.3.jar!/:5.7.3]
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:346) ~[spring-security-web-5.7.3.jar!/:5.7.3]
	at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:122) ~[spring-security-web-5.7.3.jar!/:5.7.3]
	at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:116) ~[spring-security-web-5.7.3.jar!/:5.7.3]
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:346) ~[spring-security-web-5.7.3.jar!/:5.7.3]
	at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:126) ~[spring-security-web-5.7.3.jar!/:5.7.3]
	at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:81) ~[spring-security-web-5.7.3.jar!/:5.7.3]
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:346) ~[spring-security-web-5.7.3.jar!/:5.7.3]
	at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:109) ~[spring-security-web-5.7.3.jar!/:5.7.3]
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:346) ~[spring-security-web-5.7.3.jar!/:5.7.3]
	at org.springframework.security.web.authentication.rememberme.RememberMeAuthenticationFilter.doFilter(RememberMeAuthenticationFilter.java:106) ~[spring-security-web-5.7.3.jar!/:5.7.3]
	at org.springframework.security.web.authentication.rememberme.RememberMeAuthenticationFilter.doFilter(RememberMeAuthenticationFilter.java:97) ~[spring-security-web-5.7.3.jar!/:5.7.3]
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:346) ~[spring-security-web-5.7.3.jar!/:5.7.3]
	at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:149) ~[spring-security-web-5.7.3.jar!/:5.7.3]
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:346) ~[spring-security-web-5.7.3.jar!/:5.7.3]
	at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:63) ~[spring-security-web-5.7.3.jar!/:5.7.3]
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:346) ~[spring-security-web-5.7.3.jar!/:5.7.3]
	at org.springframework.security.web.session.ConcurrentSessionFilter.doFilter(ConcurrentSessionFilter.java:147) ~[spring-security-web-5.7.3.jar!/:5.7.3]
	at org.springframework.security.web.session.ConcurrentSessionFilter.doFilter(ConcurrentSessionFilter.java:125) ~[spring-security-web-5.7.3.jar!/:5.7.3]
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:346) ~[spring-security-web-5.7.3.jar!/:5.7.3]
	at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:103) ~[spring-security-web-5.7.3.jar!/:5.7.3]
	at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:89) ~[spring-security-web-5.7.3.jar!/:5.7.3]
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:346) ~[spring-security-web-5.7.3.jar!/:5.7.3]
	at org.springframework.security.web.header.HeaderWriterFilter.doHeadersAfter(HeaderWriterFilter.java:90) ~[spring-security-web-5.7.3.jar!/:5.7.3]
	at org.springframework.security.web.header.HeaderWriterFilter.doFilterInternal(HeaderWriterFilter.java:75) ~[spring-security-web-5.7.3.jar!/:5.7.3]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.22.jar!/:5.3.22]
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:346) ~[spring-security-web-5.7.3.jar!/:5.7.3]
	at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:112) ~[spring-security-web-5.7.3.jar!/:5.7.3]
	at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:82) ~[spring-security-web-5.7.3.jar!/:5.7.3]
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:346) ~[spring-security-web-5.7.3.jar!/:5.7.3]
	at org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:55) ~[spring-security-web-5.7.3.jar!/:5.7.3]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.22.jar!/:5.3.22]
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:346) ~[spring-security-web-5.7.3.jar!/:5.7.3]
	at org.springframework.security.web.session.DisableEncodeUrlFilter.doFilterInternal(DisableEncodeUrlFilter.java:42) ~[spring-security-web-5.7.3.jar!/:5.7.3]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.22.jar!/:5.3.22]
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:346) ~[spring-security-web-5.7.3.jar!/:5.7.3]
	at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:221) ~[spring-security-web-5.7.3.jar!/:5.7.3]
	at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:186) ~[spring-security-web-5.7.3.jar!/:5.7.3]
	at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:354) ~[spring-web-5.3.22.jar!/:5.3.22]
	at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:267) ~[spring-web-5.3.22.jar!/:5.3.22]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.65.jar!/:?]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.65.jar!/:?]
	at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-5.3.22.jar!/:5.3.22]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.22.jar!/:5.3.22]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.65.jar!/:?]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.65.jar!/:?]
	at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-5.3.22.jar!/:5.3.22]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.22.jar!/:5.3.22]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.65.jar!/:?]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.65.jar!/:?]
	at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.doFilterInternal(WebMvcMetricsFilter.java:96) ~[spring-boot-actuator-2.7.3.jar!/:2.7.3]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.22.jar!/:5.3.22]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.65.jar!/:?]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.65.jar!/:?]
	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-5.3.22.jar!/:5.3.22]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.22.jar!/:5.3.22]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.65.jar!/:?]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.65.jar!/:?]
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:197) ~[tomcat-embed-core-9.0.65.jar!/:?]
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97) ~[tomcat-embed-core-9.0.65.jar!/:?]
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541) ~[tomcat-embed-core-9.0.65.jar!/:?]
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:135) ~[tomcat-embed-core-9.0.65.jar!/:?]
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) ~[tomcat-embed-core-9.0.65.jar!/:?]
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78) ~[tomcat-embed-core-9.0.65.jar!/:?]
	at org.apache.catalina.valves.RemoteIpValve.invoke(RemoteIpValve.java:769) ~[tomcat-embed-core-9.0.65.jar!/:?]
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:360) ~[tomcat-embed-core-9.0.65.jar!/:?]
	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:399) ~[tomcat-embed-core-9.0.65.jar!/:?]
	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) ~[tomcat-embed-core-9.0.65.jar!/:?]
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:890) ~[tomcat-embed-core-9.0.65.jar!/:?]
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1789) ~[tomcat-embed-core-9.0.65.jar!/:?]
	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) ~[tomcat-embed-core-9.0.65.jar!/:?]
	at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191) ~[tomcat-embed-core-9.0.65.jar!/:?]
	at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659) ~[tomcat-embed-core-9.0.65.jar!/:?]
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) ~[tomcat-embed-core-9.0.65.jar!/:?]
	at java.lang.Thread.run(Thread.java:834) ~[?:?]
Caused by: java.lang.NullPointerException
2023-01-04 11:51:05 ERROR [admin] ApplicationPageBase - admin: Export failed: NullPointerException: