org.thymeleaf.exceptions.TemplateProcessingException: Exception evaluating OGNL expression: "#handbook.urlForPage(resource, chapter)" (template: "handbook" - line 89, col 45) at org.thymeleaf.standard.expression.OGNLVariableExpressionEvaluator.evaluate(OGNLVariableExpressionEvaluator.java:199) at org.thymeleaf.standard.expression.OGNLVariableExpressionEvaluator.evaluate(OGNLVariableExpressionEvaluator.java:104) at org.thymeleaf.standard.expression.VariableExpression.executeVariableExpression(VariableExpression.java:166) at org.thymeleaf.standard.expression.SimpleExpression.executeSimple(SimpleExpression.java:66) at org.thymeleaf.standard.expression.Expression.execute(Expression.java:109) at org.thymeleaf.standard.expression.Expression.execute(Expression.java:138) at org.thymeleaf.standard.processor.AbstractStandardExpressionAttributeTagProcessor.doProcess(AbstractStandardExpressionAttributeTagProcessor.java:144) at org.thymeleaf.processor.element.AbstractAttributeTagProcessor.doProcess(AbstractAttributeTagProcessor.java:74) at org.thymeleaf.processor.element.AbstractElementTagProcessor.process(AbstractElementTagProcessor.java:95) at org.thymeleaf.util.ProcessorConfigurationUtils$ElementTagProcessorWrapper.process(ProcessorConfigurationUtils.java:633) at org.thymeleaf.engine.ProcessorTemplateHandler.handleOpenElement(ProcessorTemplateHandler.java:1314) at org.thymeleaf.engine.OpenElementTag.beHandled(OpenElementTag.java:205) at org.thymeleaf.engine.Model.process(Model.java:282) at org.thymeleaf.engine.Model.process(Model.java:290) at org.thymeleaf.engine.IteratedGatheringModelProcessable.processIterationModel(IteratedGatheringModelProcessable.java:368) at org.thymeleaf.engine.IteratedGatheringModelProcessable.process(IteratedGatheringModelProcessable.java:222) at org.thymeleaf.engine.ProcessorTemplateHandler.handleCloseElement(ProcessorTemplateHandler.java:1640) at org.thymeleaf.engine.CloseElementTag.beHandled(CloseElementTag.java:139) at org.thymeleaf.engine.TemplateModel.process(TemplateModel.java:136) at org.thymeleaf.engine.TemplateManager.parseAndProcess(TemplateManager.java:592) at org.thymeleaf.TemplateEngine.process(TemplateEngine.java:1103) at org.thymeleaf.TemplateEngine.process(TemplateEngine.java:1064) at org.thymeleaf.TemplateEngine.process(TemplateEngine.java:1053) at com.top_logic.web.template.TemplateService.processTemplate(TemplateService.java:367) at com.top_logic.web.template.rendering.AbstractResourceDisplay.render(AbstractResourceDisplay.java:35) at com.top_logic.web.template.rendering.ObjectDisplay.render(ObjectDisplay.java:58) at com.top_logic.web.model.CustomResource.doGet(CustomResource.java:39) at com.top_logic.web.servlet.ResourceServlet.doGetInContext(ResourceServlet.java:79) at com.top_logic.web.servlet.ResourceServlet.doGet(ResourceServlet.java:47) at javax.servlet.http.HttpServlet.service(HttpServlet.java:655) at com.top_logic.util.NoContextServlet.doService(NoContextServlet.java:98) at com.top_logic.util.NoContextServlet.executeInInteraction(NoContextServlet.java:47) at com.top_logic.util.NoContextServlet.service(NoContextServlet.java:38) 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 com.top_logic.knowledge.gui.layout.HttpSecureHeaderFilter.doFilter(HttpSecureHeaderFilter.java:66) 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:541) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:135) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:687) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:360) at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:399) at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:890) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1789) at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191) at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.base/java.lang.Thread.run(Thread.java:829) Caused by: ognl.MethodFailedException: Method "urlForPage" failed for object com.top_logic.dev.releasenotes.thymeleaf.HandbookThymeleafMethods@1fe278e5 [java.lang.ClassCastException: class java.util.Collections$SingletonSet cannot be cast to class com.top_logic.doc.model.Page (java.util.Collections$SingletonSet is in module java.base of loader 'bootstrap'; com.top_logic.doc.model.Page is in unnamed module of loader org.apache.catalina.loader.ParallelWebappClassLoader @6436a7db)] Caused by: java.lang.ClassCastException: class java.util.Collections$SingletonSet cannot be cast to class com.top_logic.doc.model.Page (java.util.Collections$SingletonSet is in module java.base of loader 'bootstrap'; com.top_logic.doc.model.Page is in unnamed module of loader org.apache.catalina.loader.ParallelWebappClassLoader @6436a7db) at com.top_logic.doc.model.impl.PageBase.getParent(PageBase.java:116) at com.top_logic.dev.releasenotes.thymeleaf.HandbookThymeleafMethods.appendPathToPage(HandbookThymeleafMethods.java:70) at com.top_logic.dev.releasenotes.thymeleaf.HandbookThymeleafMethods.urlForPage(HandbookThymeleafMethods.java:61) at jdk.internal.reflect.GeneratedMethodAccessor68.invoke(Unknown Source) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.base/java.lang.reflect.Method.invoke(Method.java:566) at ognl.OgnlRuntime.invokeMethodInsideSandbox(OgnlRuntime.java:1245) at ognl.OgnlRuntime.invokeMethod(OgnlRuntime.java:1230) at ognl.OgnlRuntime.callAppropriateMethod(OgnlRuntime.java:1958) at ognl.ObjectMethodAccessor.callMethod(ObjectMethodAccessor.java:68) at ognl.OgnlRuntime.callMethod(OgnlRuntime.java:2034) at ognl.ASTMethod.getValueBody(ASTMethod.java:97) at ognl.SimpleNode.evaluateGetValueBody(SimpleNode.java:212) at ognl.SimpleNode.getValue(SimpleNode.java:258) at ognl.ASTChain.getValueBody(ASTChain.java:141) at ognl.SimpleNode.evaluateGetValueBody(SimpleNode.java:212) at ognl.SimpleNode.getValue(SimpleNode.java:258) at ognl.Ognl.getValue(Ognl.java:586) at ognl.Ognl.getValue(Ognl.java:550) at org.thymeleaf.standard.expression.OGNLVariableExpressionEvaluator.executeExpression(OGNLVariableExpressionEvaluator.java:334) at org.thymeleaf.standard.expression.OGNLVariableExpressionEvaluator.evaluate(OGNLVariableExpressionEvaluator.java:178) at org.thymeleaf.standard.expression.OGNLVariableExpressionEvaluator.evaluate(OGNLVariableExpressionEvaluator.java:104) at org.thymeleaf.standard.expression.VariableExpression.executeVariableExpression(VariableExpression.java:166) at org.thymeleaf.standard.expression.SimpleExpression.executeSimple(SimpleExpression.java:66) at org.thymeleaf.standard.expression.Expression.execute(Expression.java:109) at org.thymeleaf.standard.expression.Expression.execute(Expression.java:138) at org.thymeleaf.standard.processor.AbstractStandardExpressionAttributeTagProcessor.doProcess(AbstractStandardExpressionAttributeTagProcessor.java:144) at org.thymeleaf.processor.element.AbstractAttributeTagProcessor.doProcess(AbstractAttributeTagProcessor.java:74) at org.thymeleaf.processor.element.AbstractElementTagProcessor.process(AbstractElementTagProcessor.java:95) at org.thymeleaf.util.ProcessorConfigurationUtils$ElementTagProcessorWrapper.process(ProcessorConfigurationUtils.java:633) at org.thymeleaf.engine.ProcessorTemplateHandler.handleOpenElement(ProcessorTemplateHandler.java:1314) at org.thymeleaf.engine.OpenElementTag.beHandled(OpenElementTag.java:205) at org.thymeleaf.engine.Model.process(Model.java:282) at org.thymeleaf.engine.Model.process(Model.java:290) at org.thymeleaf.engine.IteratedGatheringModelProcessable.processIterationModel(IteratedGatheringModelProcessable.java:368) at org.thymeleaf.engine.IteratedGatheringModelProcessable.process(IteratedGatheringModelProcessable.java:222) at org.thymeleaf.engine.ProcessorTemplateHandler.handleCloseElement(ProcessorTemplateHandler.java:1640) at org.thymeleaf.engine.CloseElementTag.beHandled(CloseElementTag.java:139) at org.thymeleaf.engine.TemplateModel.process(TemplateModel.java:136) at org.thymeleaf.engine.TemplateManager.parseAndProcess(TemplateManager.java:592) at org.thymeleaf.TemplateEngine.process(TemplateEngine.java:1103) at org.thymeleaf.TemplateEngine.process(TemplateEngine.java:1064) at org.thymeleaf.TemplateEngine.process(TemplateEngine.java:1053) at com.top_logic.web.template.TemplateService.processTemplate(TemplateService.java:367) at com.top_logic.web.template.rendering.AbstractResourceDisplay.render(AbstractResourceDisplay.java:35) at com.top_logic.web.template.rendering.ObjectDisplay.render(ObjectDisplay.java:58) at com.top_logic.web.model.CustomResource.doGet(CustomResource.java:39) at com.top_logic.web.servlet.ResourceServlet.doGetInContext(ResourceServlet.java:79) at com.top_logic.web.servlet.ResourceServlet.doGet(ResourceServlet.java:47) at javax.servlet.http.HttpServlet.service(HttpServlet.java:655) at com.top_logic.util.NoContextServlet.doService(NoContextServlet.java:98) at com.top_logic.util.NoContextServlet.executeInInteraction(NoContextServlet.java:47) at com.top_logic.util.NoContextServlet.service(NoContextServlet.java:38) 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 com.top_logic.knowledge.gui.layout.HttpSecureHeaderFilter.doFilter(HttpSecureHeaderFilter.java:66) 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:541) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:135) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:687) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:360) at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:399) at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:890) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1789) 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:829)