Expression cat is undefined on line 357, column 30 in blog/viewPost_B.ftl. The problematic instruction: ---------- ==> if-else [on line 357, column 25 in blog/viewPost_B.ftl] ---------- Java backtrace for programmers: ---------- freemarker.core.InvalidReferenceException: Expression cat is undefined on line 357, column 30 in blog/viewPost_B.ftl. 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$existsBI._getAsTemplateModel(BuiltIn.java:636) at freemarker.core.BuiltIn$existsBI.isTrue(BuiltIn.java:647) at freemarker.core.IfBlock.accept(IfBlock.java:80) 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:232) at org.springframework.web.servlet.view.freemarker.FreeMarkerView.processTemplate(FreeMarkerView.java:292) at org.springframework.web.servlet.view.freemarker.FreeMarkerView.doRender(FreeMarkerView.java:245) at org.springframework.web.servlet.view.freemarker.FreeMarkerView.renderMergedTemplateModel(FreeMarkerView.java:199) at org.springframework.web.servlet.view.AbstractTemplateView.renderMergedOutputModel(AbstractTemplateView.java:178) at org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:249) at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1063) at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:827) at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:736) at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:396) at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:350) at javax.servlet.http.HttpServlet.service(HttpServlet.java:624) 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.tuckey.web.filters.urlrewrite.UrlRewriteFilter.doFilter(UrlRewriteFilter.java:350) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at com.aw.common.MessageFilter.doFilter(MessageFilter.java:32) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at com.aw.common.EncodingFilter.doFilter(EncodingFilter.java:41) 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:218) 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.core.StandardEngineValve.invoke(StandardEngineValve.java:116) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:445) at org.apache.coyote.ajp.AjpProcessor.process(AjpProcessor.java:190) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:637) at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:748)