Error when export page as PDF

When export a page which title contains Chinese words as PDF ,Confluence give the flowing error:

The following error(s) occurred:
com.atlassian.confluence.importexport.ImportExportException: org.apache.velocity.exception.MethodInvocationException: Invocation of method 'exportWikiToXslFo' in class com.atlassian.confluence.importexport.impl.WikiExporter threw exception class com.atlassian.confluence.renderer.WikiRenderException : Error while generating XSL-FO for 'ESearch:综合需求分析'! at com.atlassian.confluence.importexport.impl.PdfExporter.generateXslFo(PdfExporter.java:207) at com.atlassian.confluence.importexport.impl.PdfExporter.doExportEntity(PdfExporter.java:139) at com.atlassian.confluence.importexport.impl.AbstractRendererExporterImpl.exportPage(AbstractRendererExporterImpl.java:119) at com.atlassian.confluence.importexport.impl.AbstractRendererExporterImpl.doExport(AbstractRendererExporterImpl.java:85) at com.atlassian.confluence.importexport.impl.PdfExporter.doExport(PdfExporter.java:82) at com.atlassian.confluence.importexport.DefaultImportExportManager.exportAs(DefaultImportExportManager.java:84) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:324) at org.springframework.aop.framework.AopProxyUtils.invokeJoinpointUsingReflection(AopProxyUtils.java:59) at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:149) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:118) at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:191) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:138) at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:148) at $Proxy25.exportAs(Unknown Source) at com.atlassian.confluence.importexport.actions.ExportPageAction.execute(ExportPageAction.java:99) at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:166) at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:34) at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:163) at com.opensymphony.xwork.interceptor.DefaultWorkflowInterceptor.intercept(DefaultWorkflowInterceptor.java:55) at com.atlassian.confluence.core.ConfluenceWorkflowInterceptor.intercept(ConfluenceWorkflowInterceptor.java:34) at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:163) at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:34) at com.atlassian.confluence.core.ConfluenceValidationInterceptor.intercept(ConfluenceValidationInterceptor.java:16) at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:163) at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:34) at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:163) at com.atlassian.confluence.security.actions.PermissionCheckInterceptor.intercept(PermissionCheckInterceptor.java:40) at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:163) at com.atlassian.confluence.pages.actions.PageAwareInterceptor.intercept(PageAwareInterceptor.java:73) at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:163) at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:34) at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:163) at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:34) at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:163) at com.atlassian.confluence.core.ConfluenceAutowireInterceptor.intercept(ConfluenceAutowireInterceptor.java:25) at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:163) at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:34) at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:163) at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:34) at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:163) at com.atlassian.confluence.util.XWorkTransactionInterceptor.intercept(XWorkTransactionInterceptor.java:124) at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:163) at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:34) at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:163) at com.opensymphony.xwork.DefaultActionProxy.execute(DefaultActionProxy.java:115) at com.opensymphony.webwork.dispatcher.ServletDispatcher.serviceAction(ServletDispatcher.java:278) at com.opensymphony.webwork.dispatcher.ServletDispatcher.service(ServletDispatcher.java:248) at javax.servlet.http.HttpServlet.service(HttpServlet.java:853) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:247) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193) at com.opensymphony.module.sitemesh.filter.PageFilter.parsePage(PageFilter.java:145) at com.atlassian.confluence.util.profiling.ProfilingPageFilter.parsePage(ProfilingPageFilter.java:146) at com.opensymphony.module.sitemesh.filter.PageFilter.doFilter(PageFilter.java:61) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:213) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193) at com.atlassian.seraph.filter.SecurityFilter.doFilter(SecurityFilter.java:165) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:213) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193) at com.atlassian.seraph.filter.LoginFilter.doFilter(LoginFilter.java:181) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:213) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193) at com.atlassian.johnson.filters.JohnsonFilter.doFilter(JohnsonFilter.java:96) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:213) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193) at org.springframework.orm.hibernate.support.OpenSessionInViewFilter.doFilterInternal(OpenSessionInViewFilter.java:117) at bucket.custom.FlushingSpringSessionInViewFilter.doFilterInternal(FlushingSpringSessionInViewFilter.java:30) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:73) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:213) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193) at com.atlassian.util.profiling.filters.ProfilingFilter.doFilter(ProfilingFilter.java:132) at com.atlassian.confluence.util.error.ProfilingAndErrorFilter.doFilter(ProfilingAndErrorFilter.java:25) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:213) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193) at com.atlassian.core.filters.AbstractEncodingFilter.doFilter(AbstractEncodingFilter.java:38) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:213) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:256) at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643) at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480) at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191) at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643) at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480) at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995) at org.apache.catalina.core.StandardContext.invoke(StandardContext.java:2417) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:180) at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643) at org.apache.catalina.valves.ErrorDispatcherValve.invoke(ErrorDispatcherValve.java:171) at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:641) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:172) at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:641) at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480) at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:174) at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643) at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480) at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995) at org.apache.coyote.tomcat4.CoyoteAdapter.service(CoyoteAdapter.java:193) at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:781) at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:549) at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:589) at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:666) at java.lang.Thread.run(Thread.java:534) Caused by: org.apache.velocity.exception.MethodInvocationException: Invocation of method 'exportWikiToXslFo' in class com.atlassian.confluence.importexport.impl.WikiExporter threw exception class com.atlassian.confluence.renderer.WikiRenderException : Error while generating XSL-FO for 'ESearch:综合需求分析'! at org.apache.velocity.runtime.parser.node.ASTMethod.execute(ASTMethod.java:309) at org.apache.velocity.runtime.parser.node.ASTReference.execute(ASTReference.java:207) at org.apache.velocity.runtime.parser.node.ASTReference.render(ASTReference.java:250) at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:271) at org.apache.velocity.Template.merge(Template.java:296) at com.atlassian.confluence.util.TemplateSupport.processTemplate(TemplateSupport.java:56) at com.atlassian.confluence.importexport.impl.PdfExporter.generateXslFo(PdfExporter.java:203) ... 105 more