FreeMarker template error (HTML_DEBUG mode; use RETHROW in production!)

The following has evaluated to null or missing:
==> siteMgr  [in template "WEB-INF/views/_Layout/program/inc/inc.Header_sciencegifted.ftl" at line 16, column 43]

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Tip: If the failing expression is known to legally refer to something that's sometimes null or missing, either specify a default value like myOptionalVar!myDefault, or use <#if myOptionalVar??>when-present<#else>when-missing</#if>. (These only cover the last step of the expression; to cover the whole expression, use parenthesis: (myOptionalVar.foo)!myDefault, (myOptionalVar.foo)??
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FTL stack trace ("~" means nesting-related):
	- Failed at: ${siteMgr.layout!}  [in template "WEB-INF/views/_Layout/program/inc/inc.Header_sciencegifted.ftl" at line 16, column 41]
	- Reached through: #include "/WEB-INF/views/_Layout/prog...  [in template "WEB-INF/views/_Layout/program/core/coreHeader.ftl" at line 33, column 1]
	- Reached through: #include "/WEB-INF/views/_Layout/prog...  [in template "WEB-INF/views/_Layout/layout/introLayout.ftl" at line 5, column 17]
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Java stack trace (for programmers):
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freemarker.core.InvalidReferenceException: [... Exception message was already printed; see it above ...]
	at freemarker.core.InvalidReferenceException.getInstance(InvalidReferenceException.java:134)
	at freemarker.core.UnexpectedTypeException.newDesciptionBuilder(UnexpectedTypeException.java:85)
	at freemarker.core.UnexpectedTypeException.<init>(UnexpectedTypeException.java:48)
	at freemarker.core.NonHashException.<init>(NonHashException.java:49)
	at freemarker.core.Dot._eval(Dot.java:48)
	at freemarker.core.Expression.eval(Expression.java:83)
	at freemarker.core.DefaultToExpression._eval(DefaultToExpression.java:88)
	at freemarker.core.Expression.eval(Expression.java:83)
	at freemarker.core.DollarVariable.calculateInterpolatedStringOrMarkup(DollarVariable.java:100)
	at freemarker.core.DollarVariable.accept(DollarVariable.java:63)
	at freemarker.core.Environment.visit(Environment.java:330)
	at freemarker.core.Environment.visit(Environment.java:336)
	at freemarker.core.Environment.include(Environment.java:2582)
	at freemarker.core.Include.accept(Include.java:171)
	at freemarker.core.Environment.visit(Environment.java:330)
	at freemarker.core.Environment.visit(Environment.java:336)
	at freemarker.core.Environment.visit(Environment.java:336)
	at freemarker.core.Environment.include(Environment.java:2582)
	at freemarker.core.Include.accept(Include.java:171)
	at freemarker.core.Environment.visit(Environment.java:330)
	at freemarker.core.Environment.visit(Environment.java:336)
	at freemarker.core.Environment.process(Environment.java:309)
	at freemarker.ext.servlet.FreemarkerServlet.processEnvironment(FreemarkerServlet.java:910)
	at freemarker.ext.servlet.FreemarkerServlet.process(FreemarkerServlet.java:879)
	at freemarker.ext.servlet.FreemarkerServlet.doGet(FreemarkerServlet.java:764)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:734)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:847)
	at jeus.servlet.engine.ServletWrapper.executeServlet(ServletWrapper.java:172)
	at jeus.servlet.engine.RequestDispatcherImpl.processCommonRequestDispatcher(RequestDispatcherImpl.java:537)
	at jeus.servlet.engine.RequestDispatcherImpl.doForward(RequestDispatcherImpl.java:454)
	at jeus.servlet.engine.RequestDispatcherImpl.forward(RequestDispatcherImpl.java:381)
	at org.apache.tiles.servlet.context.ServletTilesRequestContext.forward(ServletTilesRequestContext.java:241)
	at org.apache.tiles.servlet.context.ServletTilesRequestContext.dispatch(ServletTilesRequestContext.java:222)
	at org.apache.tiles.renderer.impl.TemplateAttributeRenderer.write(TemplateAttributeRenderer.java:44)
	at org.apache.tiles.renderer.impl.AbstractBaseAttributeRenderer.render(AbstractBaseAttributeRenderer.java:106)
	at org.apache.tiles.impl.BasicTilesContainer.render(BasicTilesContainer.java:670)
	at org.apache.tiles.impl.BasicTilesContainer.render(BasicTilesContainer.java:690)
	at org.apache.tiles.impl.BasicTilesContainer.render(BasicTilesContainer.java:644)
	at org.apache.tiles.impl.BasicTilesContainer.render(BasicTilesContainer.java:627)
	at org.apache.tiles.impl.BasicTilesContainer.render(BasicTilesContainer.java:321)
	at org.springframework.web.servlet.view.tiles2.TilesView.renderMergedOutputModel(TilesView.java:112)
	at org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:303)
	at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1286)
	at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1041)
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:984)
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901)
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
	at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:734)
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:847)
	at jeus.servlet.engine.ServletWrapper.executeServlet(ServletWrapper.java:172)
	at jeus.servlet.filter.FilterChainImpl.internalDoFilter(FilterChainImpl.java:112)
	at jeus.servlet.filter.FilterChainImpl.doFilter(FilterChainImpl.java:86)
	at org.springframework.mobile.device.DeviceResolverRequestFilter.doFilterInternal(DeviceResolverRequestFilter.java:60)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
	at jeus.servlet.filter.FilterChainImpl.internalDoFilter(FilterChainImpl.java:98)
	at jeus.servlet.filter.FilterChainImpl.doFilter(FilterChainImpl.java:86)
	at centum.filter.HTMLTagFilter.doFilter(HTMLTagFilter.java:21)
	at jeus.servlet.filter.FilterChainImpl.internalDoFilter(FilterChainImpl.java:98)
	at jeus.servlet.filter.FilterChainImpl.doFilter(FilterChainImpl.java:86)
	at centum.filter.HttpsFilter.doFilter(HttpsFilter.java:24)
	at jeus.servlet.filter.FilterChainImpl.internalDoFilter(FilterChainImpl.java:98)
	at jeus.servlet.filter.FilterChainImpl.doFilter(FilterChainImpl.java:86)
	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
	at jeus.servlet.filter.FilterChainImpl.internalDoFilter(FilterChainImpl.java:98)
	at jeus.servlet.filter.FilterChainImpl.doFilter(FilterChainImpl.java:86)
	at jeus.servlet.engine.ServletWrapper.execute(ServletWrapper.java:147)
	at jeus.servlet.engine.RequestProcessor.run(RequestProcessor.java:211)
	at jeus.util.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:1211)
	at jeus.util.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:1261)
	at jeus.servlet.engine.WebThreadPoolExecutor$WebRequestWorker.run(WebThreadPoolExecutor.java:340)
	at java.lang.Thread.run(Thread.java:785)