Struts Problem Report

Struts has detected an unhandled exception:

Messages:
File: org/apache/struts2/views/tiles/TilesResult.java
Line number: 105

Stacktraces

java.lang.NullPointerException
    org.apache.struts2.views.tiles.TilesResult.doExecute(TilesResult.java:105)
    org.apache.struts2.dispatcher.StrutsResultSupport.execute(StrutsResultSupport.java:186)
    com.opensymphony.xwork2.DefaultActionInvocation.executeResult(DefaultActionInvocation.java:371)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:275)
    org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:54)
    org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:562)
    org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
    org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:99)
    org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:168)
    org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:144)
    ProxyFilter.doFilter(ProxyFilter.java:39)
    org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:168)
    org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:144)
    org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:168)
    org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:90)
    org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:596)
    org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:130)
    org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:93)
    org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:660)
    org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
    org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:346)
    org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:388)
    org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:63)
    org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:928)
    org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1791)
    org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:52)
    org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1190)
    org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659)
    org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:63)
    java.base/java.lang.Thread.run(Thread.java:834)