<#if myOptionalVar??>when-present<#else>when-missing. (These only cover the last step of the expression; to cover the whole expression, use parenthesis: (myOptionalVar.foo)!myDefault, (myOptionalVar.foo)?? ---- ---- FTL stack trace ("~" means nesting-related): - Failed at: ${domainButtonSize} [in template "default/header.htm" at line 89, column 30] - Reached through: #include "header.htm" [in template "default/message.htm" at line 1, column 1] - Reached through: #include "default/message.htm" [in template "exception.html" at line 26, column 17] ---- Java stack trace (for programmers): ---- freemarker.core.InvalidReferenceException: [... Exception message was already printed; see it above ...] at freemarker.core.InvalidReferenceException.getInstance(InvalidReferenceException.java:134) at freemarker.core.EvalUtil.coerceModelToTextualCommon(EvalUtil.java:490) at freemarker.core.EvalUtil.coerceModelToStringOrMarkup(EvalUtil.java:410) at freemarker.core.EvalUtil.coerceModelToStringOrMarkup(EvalUtil.java:379) at freemarker.core.DollarVariable.calculateInterpolatedStringOrMarkup(DollarVariable.java:104) at freemarker.core.DollarVariable.accept(DollarVariable.java:63) at freemarker.core.Environment.visit(Environment.java:344) at freemarker.core.Environment.visit(Environment.java:350) at freemarker.core.Environment.include(Environment.java:3139) at freemarker.core.Include.accept(Include.java:171) at freemarker.core.Environment.visit(Environment.java:344) at freemarker.core.Environment.visit(Environment.java:350) at freemarker.core.Environment.include(Environment.java:3139) at freemarker.core.Include.accept(Include.java:171) at freemarker.core.Environment.visit(Environment.java:344) at freemarker.core.Environment.visit(Environment.java:350) at freemarker.core.Environment.visit(Environment.java:350) at freemarker.core.Environment.visit(Environment.java:350) at freemarker.core.Environment.process(Environment.java:323) at freemarker.template.Template.process(Template.java:383) at net.jforum.exceptions.ExceptionWriter.handleExceptionData(ExceptionWriter.java:129) at net.jforum.exceptions.ExceptionWriter.handleExceptionData(ExceptionWriter.java:76) at net.jforum.JForum.handleException(JForum.java:338) at net.jforum.JForum.service(JForum.java:238) at jakarta.servlet.http.HttpServlet.service(HttpServlet.java:716) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:130) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:109) at com.javaranch.jforum.url.JSessionIDFilter.doFilter(JSessionIDFilter.java:27) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:109) at com.javaranch.jforum.url.UrlFilter.doChain(UrlFilter.java:72) at com.javaranch.jforum.url.UrlFilter.doFilter(UrlFilter.java:55) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:109) at net.jforum.BotOverloadFilter.doFilter(BotOverloadFilter.java:51) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:109) at net.jforum.util.legacy.clickstream.ClickstreamFilter.doFilter(ClickstreamFilter.java:48) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:109) at net.jforum.JpaFilter.doFilter(JpaFilter.java:23) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:109) at net.jforum.ResponseHeadersFilter.doFilter(ResponseHeadersFilter.java:22) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:109) at com.javaranch.jforum.csrf.CsrfFilter.doFilter(CsrfFilter.java:92) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:109) at net.jforum.JForumExecutionContextFilter.doFilter(JForumExecutionContextFilter.java:22) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:109) at net.jforum.UrlMultiSlashFilter.doFilter(UrlMultiSlashFilter.java:27) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:109) at net.jforum.JForumRequestCharacterEncodingFilter.doFilter(JForumRequestCharacterEncodingFilter.java:29) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:109) at net.jforum.TrackbackFilter.doFilter(TrackbackFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:109) at net.jforum.PrematureRequestFilter.doFilter(PrematureRequestFilter.java:31) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:109) at net.jforum.AccessBanFilter.doFilter(AccessBanFilter.java:49) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:109) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:167) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:79) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:483) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:115) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:93) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342) at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:382) at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:63) at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:905) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1746) at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:52) at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1148) at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:636) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:63) at java.base/java.lang.Thread.run(Thread.java:840)