Expression board is undefined on line 439, column 100 in WEB-INF/templates/view/board/show.html.
The problematic instruction:
----------
==> ${board.id?if_exists} [on line 439, column 98 in WEB-INF/templates/view/board/show.html]
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Java backtrace for programmers:
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freemarker.core.InvalidReferenceException: Expression board is undefined on line 439, column 100 in WEB-INF/templates/view/board/show.html.
	at freemarker.core.TemplateObject.assertNonNull(TemplateObject.java:124)
	at freemarker.core.TemplateObject.invalidTypeException(TemplateObject.java:134)
	at freemarker.core.Dot._getAsTemplateModel(Dot.java:78)
	at freemarker.core.Expression.getAsTemplateModel(Expression.java:89)
	at freemarker.core.BuiltIn$if_existsBI._getAsTemplateModel(BuiltIn.java:676)
	at freemarker.core.Expression.getAsTemplateModel(Expression.java:89)
	at freemarker.core.Expression.getStringValue(Expression.java:93)
	at freemarker.core.DollarVariable.accept(DollarVariable.java:76)
	at freemarker.core.Environment.visit(Environment.java:196)
	at freemarker.core.MixedContent.accept(MixedContent.java:92)
	at freemarker.core.Environment.visit(Environment.java:196)
	at freemarker.core.IteratorBlock$Context.runLoop(IteratorBlock.java:160)
	at freemarker.core.Environment.visit(Environment.java:351)
	at freemarker.core.IteratorBlock.accept(IteratorBlock.java:95)
	at freemarker.core.Environment.visit(Environment.java:196)
	at freemarker.core.MixedContent.accept(MixedContent.java:92)
	at freemarker.core.Environment.visit(Environment.java:196)
	at freemarker.core.ConditionalBlock.accept(ConditionalBlock.java:79)
	at freemarker.core.Environment.visit(Environment.java:196)
	at freemarker.core.MixedContent.accept(MixedContent.java:92)
	at freemarker.core.Environment.visit(Environment.java:196)
	at freemarker.core.Environment.process(Environment.java:176)
	at freemarker.template.Template.process(Template.java:231)
	at com.opensymphony.webwork.views.freemarker.FreemarkerServlet.process(FreemarkerServlet.java:223)
	at com.opensymphony.webwork.views.freemarker.FreemarkerServlet.doGet(FreemarkerServlet.java:45)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:689)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:237)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)
	at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:704)
	at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:474)
	at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:409)
	at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:312)
	at com.opensymphony.webwork.dispatcher.ServletDispatcherResult.doExecute(ServletDispatcherResult.java:114)
	at com.opensymphony.webwork.dispatcher.WebWorkResultSupport.execute(WebWorkResultSupport.java:101)
	at com.opensymphony.xwork.DefaultActionInvocation.executeResult(DefaultActionInvocation.java:300)
	at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:198)
	at com.zframework.system.interceptor.ExceptionHandlerInterceptor.intercept(ExceptionHandlerInterceptor.java:62)
	at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:180)
	at com.opensymphony.xwork.interceptor.DefaultWorkflowInterceptor.intercept(DefaultWorkflowInterceptor.java:125)
	at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:180)
	at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:32)
	at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:180)
	at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:32)
	at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:180)
	at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:32)
	at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:180)
	at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:32)
	at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:180)
	at com.opensymphony.webwork.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:136)
	at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:180)
	at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:32)
	at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:180)
	at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:32)
	at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:180)
	at com.opensymphony.xwork.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:146)
	at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:180)
	at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:32)
	at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:180)
	at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:32)
	at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:180)
	at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:32)
	at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:180)
	at com.opensymphony.xwork.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:94)
	at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:180)
	at com.opensymphony.xwork.DefaultActionProxy.execute(DefaultActionProxy.java:113)
	at com.opensymphony.webwork.dispatcher.DispatcherUtils.serviceAction(DispatcherUtils.java:202)
	at com.opensymphony.webwork.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:184)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:186)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)
	at org.springframework.orm.hibernate3.support.OpenSessionInViewFilter.doFilterInternal(OpenSessionInViewFilter.java:174)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:186)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)
	at com.zframework.system.filter.GZIPFilter.doFilter(GZIPFilter.java:59)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:186)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)
	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:75)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:186)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)
	at com.opensymphony.clickstream.ClickstreamFilter.doFilter(ClickstreamFilter.java:56)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:186)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)
	at com.opensymphony.clickstream.ClickstreamFilter.doFilter(ClickstreamFilter.java:56)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:186)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:214)
	at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
	at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
	at org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:198)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:152)
	at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
	at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:137)
	at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:118)
	at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:102)
	at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:535)
	at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:102)
	at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
	at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
	at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
	at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:929)
	at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:160)
	at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:799)
	at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:705)
	at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:577)
	at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:683)
	at java.lang.Thread.run(Thread.java:595)