Expression article is undefined on line 14, column 10 in PageMasterTemplate. The problematic instruction: ---------- ==> ${article.title} [on line 14, column 8 in PageMasterTemplate] ---------- Java backtrace for programmers: ---------- freemarker.core.InvalidReferenceException: Expression article is undefined on line 14, column 10 in PageMasterTemplate. 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.Expression.getStringValue(Expression.java:93) at freemarker.core.DollarVariable.accept(DollarVariable.java:76) at freemarker.core.Environment.visit(Environment.java:210) at freemarker.core.MixedContent.accept(MixedContent.java:92) at freemarker.core.Environment.visit(Environment.java:210) at freemarker.core.Environment.process(Environment.java:190) at freemarker.template.Template.process(Template.java:237) at com.sbc.controllers.PageController.processSiteTemplateFile(PageController.java:145) at com.sbc.controllers.PageController.processRequest(PageController.java:92) at com.sbc.controllers.PageController.doGet(PageController.java:258) at javax.servlet.http.HttpServlet.service(HttpServlet.java:655) at javax.servlet.http.HttpServlet.service(HttpServlet.java:764) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:227) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:197) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:540) at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:687) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:135) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:357) at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:382) at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:895) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1722) at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191) at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.base/java.lang.Thread.run(Thread.java:840)