FreeMarker template error: The following has evaluated to null or missing: ==> channel.parent [in template "WEB-INF/t/cms/dzxxgcxy/dzxxgcxy/channel/news.html" at line 33, column 26] Tip: If the failing expression is known to be legally null/missing, either specify a default value with myOptionalVar!myDefault, or use [#if myOptionalVar??]when-present[#else]when-missing[/#if]. (These only cover the last step of the expression; to cover the whole expression, use parenthessis: (myOptionVar.foo)!myDefault, (myOptionVar.foo)?? The failing instruction (FTL stack trace): ---------- ==> #assign aa = channel.parent.id?number [in template "WEB-INF/t/cms/dzxxgcxy/dzxxgcxy/channel/news.html" at line 33, column 14] ---------- Java stack trace (for programmers): ---------- freemarker.core.InvalidReferenceException: [... Exception message was already printed; see it above ...] at freemarker.core.InvalidReferenceException.getInstance(InvalidReferenceException.java:98) at freemarker.core.UnexpectedTypeException.newDesciptionBuilder(UnexpectedTypeException.java:41) at freemarker.core.UnexpectedTypeException.(UnexpectedTypeException.java:24) at freemarker.core.Dot._eval(Dot.java:81) at freemarker.core.Expression.eval(Expression.java:111) at freemarker.core.Expression.evalAndCoerceToString(Expression.java:115) at freemarker.core.StringBuiltins$StringBuiltIn._eval(StringBuiltins.java:87) at freemarker.core.Expression.eval(Expression.java:111) at freemarker.core.Assignment.accept(Assignment.java:106) at freemarker.core.Environment.visitByHiddingParent(Environment.java:286) at freemarker.core.ConditionalBlock.accept(ConditionalBlock.java:86) at freemarker.core.Environment.visit(Environment.java:265) at freemarker.core.MixedContent.accept(MixedContent.java:93) at freemarker.core.Environment.visit(Environment.java:265) at freemarker.core.Environment.process(Environment.java:243) at freemarker.template.Template.process(Template.java:277) at com.jeecms.common.web.springmvc.SimpleFreeMarkerView.renderMergedTemplateModel(SimpleFreeMarkerView.java:114) at org.springframework.web.servlet.view.AbstractTemplateView.renderMergedOutputModel(AbstractTemplateView.java:167) at org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:263) at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1208) at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:992) at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:939) at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:856) at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:936) at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:827) at javax.servlet.http.HttpServlet.service(HttpServlet.java:624) at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:812) at javax.servlet.http.HttpServlet.service(HttpServlet.java:731) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.shiro.web.servlet.AbstractShiroFilter.executeChain(AbstractShiroFilter.java:449) at org.apache.shiro.web.servlet.AbstractShiroFilter$1.call(AbstractShiroFilter.java:365) at org.apache.shiro.subject.support.SubjectCallable.doCall(SubjectCallable.java:90) at org.apache.shiro.subject.support.SubjectCallable.call(SubjectCallable.java:83) at org.apache.shiro.subject.support.DelegatingSubject.execute(DelegatingSubject.java:383) at org.apache.shiro.web.servlet.AbstractShiroFilter.doFilterInternal(AbstractShiroFilter.java:362) at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125) at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:343) at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:260) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.springframework.orm.hibernate3.support.OpenSessionInViewFilter.doFilterInternal(OpenSessionInViewFilter.java:230) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at com.jeecms.common.web.ProcessTimeFilter.doFilter(ProcessTimeFilter.java:35) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:110) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:506) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103) at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:962) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:445) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1115) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:637) at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2555) at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2544) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:744)