Unknown XStream exception; nested exception is java.lang.NullPointerExceptionorg.springframework.oxm.xstream.XStreamMarshaller:558org.springframework.oxm.UncategorizedMappingException: Unknown XStream exception; nested exception is java.lang.NullPointerException at org.springframework.oxm.xstream.XStreamMarshaller.convertXStreamException(XStreamMarshaller.java:558) at org.springframework.oxm.xstream.XStreamMarshaller.marshal(XStreamMarshaller.java:458) at org.springframework.oxm.xstream.XStreamMarshaller.marshalWriter(XStreamMarshaller.java:445) at org.springframework.oxm.xstream.XStreamMarshaller.marshalOutputStream(XStreamMarshaller.java:427) at org.springframework.oxm.support.AbstractMarshaller.marshalStreamResult(AbstractMarshaller.java:267) at org.springframework.oxm.support.AbstractMarshaller.marshal(AbstractMarshaller.java:102) at org.springframework.http.converter.xml.MarshallingHttpMessageConverter.writeToResult(MarshallingHttpMessageConverter.java:131) at org.springframework.http.converter.xml.AbstractXmlHttpMessageConverter.writeInternal(AbstractXmlHttpMessageConverter.java:66) at org.springframework.http.converter.AbstractHttpMessageConverter.write(AbstractHttpMessageConverter.java:181) at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter$ServletHandlerMethodInvoker.writeWithMessageConverters(AnnotationMethodHandlerAdapter.java:975) at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter$ServletHandlerMethodInvoker.handleResponseBody(AnnotationMethodHandlerAdapter.java:933) at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter$ServletHandlerMethodInvoker.getModelAndView(AnnotationMethodHandlerAdapter.java:882) at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:428) at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:414) at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:790) at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:719) at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:644) at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:549) at javax.servlet.http.HttpServlet.service(HttpServlet.java:617) at javax.servlet.http.HttpServlet.service(HttpServlet.java:717) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.openmrs.module.web.filter.ForcePasswordChangeFilter.doFilter(ForcePasswordChangeFilter.java:65) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.openmrs.module.web.filter.ModuleFilterChain.doFilter(ModuleFilterChain.java:76) at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:83) at org.openmrs.module.logmanager.web.filter.RequestProviderFilter.doFilterInternal(RequestProviderFilter.java:36) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76) at org.openmrs.module.web.filter.ModuleFilterChain.doFilter(ModuleFilterChain.java:74) at org.openmrs.web.filter.GZIPFilter.doFilterInternal(GZIPFilter.java:59) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76) at org.openmrs.module.web.filter.ModuleFilterChain.doFilter(ModuleFilterChain.java:74) at org.openmrs.module.webservices.rest.web.filter.AuthorizationFilter.doFilter(AuthorizationFilter.java:108) at org.openmrs.module.web.filter.ModuleFilterChain.doFilter(ModuleFilterChain.java:74) at org.springframework.web.filter.ShallowEtagHeaderFilter.doFilterInternal(ShallowEtagHeaderFilter.java:58) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76) at org.openmrs.module.web.filter.ModuleFilterChain.doFilter(ModuleFilterChain.java:74) at org.openmrs.module.web.filter.ModuleFilter.doFilter(ModuleFilter.java:58) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.openmrs.web.filter.OpenmrsFilter.doFilterInternal(OpenmrsFilter.java:111) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.springframework.orm.hibernate3.support.OpenSessionInViewFilter.doFilterInternal(OpenSessionInViewFilter.java:198) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.openmrs.web.filter.StartupFilter.doFilter(StartupFilter.java:109) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.openmrs.web.filter.StartupFilter.doFilter(StartupFilter.java:109) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.openmrs.web.filter.StartupFilter.doFilter(StartupFilter.java:109) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293) at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859) at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:602) at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489) at java.lang.Thread.run(Thread.java:745) Caused by: java.lang.NullPointerException at org.openmrs.module.webservices.rest.util.SimpleObjectConverter.getSelfLink(SimpleObjectConverter.java:76) at org.openmrs.module.webservices.rest.util.SimpleObjectConverter.marshal(SimpleObjectConverter.java:49) at org.openmrs.module.webservices.rest.util.SimpleObjectConverter.marshal(SimpleObjectConverter.java:41) at com.thoughtworks.xstream.core.AbstractReferenceMarshaller.convert(AbstractReferenceMarshaller.java:68) at com.thoughtworks.xstream.core.TreeMarshaller.convertAnother(TreeMarshaller.java:78) at com.thoughtworks.xstream.core.TreeMarshaller.convertAnother(TreeMarshaller.java:63) at com.thoughtworks.xstream.core.TreeMarshaller.start(TreeMarshaller.java:98) at com.thoughtworks.xstream.core.AbstractTreeMarshallingStrategy.marshal(AbstractTreeMarshallingStrategy.java:38) at com.thoughtworks.xstream.XStream.marshal(XStream.java:837) at com.thoughtworks.xstream.XStream.marshal(XStream.java:826) at org.springframework.oxm.xstream.XStreamMarshaller.marshal(XStreamMarshaller.java:455) ... 70 more