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

The string doesn't match the expected date/time/date-time format. The string to parse was: "". The expected format was: "yyyy-MM-dd HH:mm:ss".
The nested reason given follows:
Unparseable date: ""

----
FTL stack trace ("~" means nesting-related):
	- Failed at: ${news.pubDt?datetime!""}  [in template "fses/detail.html" at line 56, column 77]
----

Java stack trace (for programmers):
----
freemarker.core._TemplateModelException: [... Exception message was already printed; see it above ...]
	at freemarker.core.BuiltInsForMultipleTypes$dateBI$DateParser.parse(BuiltInsForMultipleTypes.java:193)
	at freemarker.core.BuiltInsForMultipleTypes$dateBI$DateParser.getAsDate(BuiltInsForMultipleTypes.java:166)
	at freemarker.core.EvalUtil.modelToDate(EvalUtil.java:84)
	at freemarker.core.Environment.formatDate(Environment.java:1178)
	at freemarker.core.EvalUtil.coerceModelToString(EvalUtil.java:347)
	at freemarker.core.Expression.evalAndCoerceToString(Expression.java:82)
	at freemarker.core.DollarVariable.accept(DollarVariable.java:41)
	at freemarker.core.Environment.visit(Environment.java:324)
	at freemarker.core.MixedContent.accept(MixedContent.java:54)
	at freemarker.core.Environment.visit(Environment.java:324)
	at freemarker.core.Environment.process(Environment.java:302)
	at freemarker.template.Template.process(Template.java:325)
	at org.esbuilder.spring.web.servlet.view.freemarker.ExtRichFreeMarkerView.processTemplate(ExtRichFreeMarkerView.java:330)
	at org.esbuilder.spring.web.servlet.view.freemarker.ExtRichFreeMarkerView.doRender(ExtRichFreeMarkerView.java:214)
	at org.esbuilder.spring.web.servlet.view.freemarker.ExtRichFreeMarkerView.renderMergedTemplateModel(ExtRichFreeMarkerView.java:165)
	at org.springframework.web.servlet.view.AbstractTemplateView.renderMergedOutputModel(AbstractTemplateView.java:167)
	at org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:262)
	at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1180)
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:950)
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:852)
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:882)
	at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:778)
	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 com.alibaba.druid.support.http.WebStatFilter.doFilter(WebStatFilter.java:123)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
	at org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:61)
	at org.apache.shiro.web.servlet.AdviceFilter.executeChain(AdviceFilter.java:108)
	at org.apache.shiro.web.servlet.AdviceFilter.doFilterInternal(AdviceFilter.java:137)
	at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125)
	at org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:66)
	at org.apache.shiro.web.servlet.AbstractShiroFilter.executeChain(AbstractShiroFilter.java:449)
	at org.apache.shiro.web.servlet.AbstractShiroFilter$1.call(AbstractShiroFilter.java:365)
	at org.apache.shiro.subject.support.SubjectCallable.doCall(SubjectCallable.java:90)
	at org.apache.shiro.subject.support.SubjectCallable.call(SubjectCallable.java:83)
	at org.apache.shiro.subject.support.DelegatingSubject.execute(DelegatingSubject.java:383)
	at org.apache.shiro.web.servlet.AbstractShiroFilter.doFilterInternal(AbstractShiroFilter.java:362)
	at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125)
	at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:346)
	at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:259)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
	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:219)
	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.valves.AccessLogValve.invoke(AccessLogValve.java:962)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:445)
	at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1115)
	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$WrappingRunnable.run(TaskThread.java:61)
	at java.lang.Thread.run(Thread.java:748)
Caused by: java.text.ParseException: Unparseable date: ""
	at java.text.DateFormat.parse(DateFormat.java:366)
	at freemarker.core.JavaTemplateDateFormat.parse(JavaTemplateDateFormat.java:43)
	at freemarker.core.BuiltInsForMultipleTypes$dateBI$DateParser.parse(BuiltInsForMultipleTypes.java:185)
	... 66 more