Good morning staff
I'm new here in the forum and would like to have your help!
I am conducting a system with Struts2 more every time I run the system I encounter the following error:

Java Code:
2011-09-29 08:37:48,685 ERROR [org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/scg2]] - <Exception starting filter Struts2DispatcherFilter>
java.lang.NullPointerException
	at com.opensymphony.xwork2.util.FileManager$FileRevision.needsReloading(FileManager.java:209)
	at com.opensymphony.xwork2.util.FileManager.fileNeedsReloading(FileManager.java:60)
	at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.needsReload(XmlConfigurationProvider.java:325)
	at org.apache.struts2.config.StrutsXmlConfigurationProvider.needsReload(StrutsXmlConfigurationProvider.java:168)
	at com.opensymphony.xwork2.config.ConfigurationManager.conditionalReload(ConfigurationManager.java:220)
	at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:61)
	at org.apache.struts2.dispatcher.Dispatcher.getContainer(Dispatcher.java:774)
	at org.apache.struts2.dispatcher.ng.InitOperations.initStaticContentLoader(InitOperations.java:77)
	at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.init(StrutsPrepareAndExecuteFilter.java:49)
	at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:221)
	at org.apache.catalina.core.ApplicationFilterConfig.setFilterDef(ApplicationFilterConfig.java:302)
	at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:78)
	at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:3635)
	at org.apache.catalina.core.StandardContext.start(StandardContext.java:4222)
	at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:760)
	at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:740)
	at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:544)
	at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:920)
	at org.apache.catalina.startup.HostConfig.deployDirectories(HostConfig.java:883)
	at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:492)
	at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1138)
	at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:311)
	at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:120)
	at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1022)
	at org.apache.catalina.core.StandardHost.start(StandardHost.java:736)
	at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1014)
	at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:443)
	at org.apache.catalina.core.StandardService.start(StandardService.java:448)
	at org.apache.catalina.core.StandardServer.start(StandardServer.java:700)
	at org.apache.catalina.startup.Catalina.start(Catalina.java:552)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:295)
	at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:433)
2011-09-29 08:37:48,685 ERROR [org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/scg2]] - <Exception starting filter Struts2DispatcherFilter>
java.lang.NullPointerException
	at com.opensymphony.xwork2.util.FileManager$FileRevision.needsReloading(FileManager.java:209)
	at com.opensymphony.xwork2.util.FileManager.fileNeedsReloading(FileManager.java:60)
	at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.needsReload(XmlConfigurationProvider.java:325)
	at org.apache.struts2.config.StrutsXmlConfigurationProvider.needsReload(StrutsXmlConfigurationProvider.java:168)
	at com.opensymphony.xwork2.config.ConfigurationManager.conditionalReload(ConfigurationManager.java:220)
	at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:61)
	at org.apache.struts2.dispatcher.Dispatcher.getContainer(Dispatcher.java:774)
	at org.apache.struts2.dispatcher.ng.InitOperations.initStaticContentLoader(InitOperations.java:77)
	at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.init(StrutsPrepareAndExecuteFilter.java:49)
	at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:221)
	at org.apache.catalina.core.ApplicationFilterConfig.setFilterDef(ApplicationFilterConfig.java:302)
	at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:78)
	at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:3635)
	at org.apache.catalina.core.StandardContext.start(StandardContext.java:4222)
	at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:760)
	at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:740)
	at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:544)
	at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:920)
	at org.apache.catalina.startup.HostConfig.deployDirectories(HostConfig.java:883)
	at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:492)
	at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1138)
	at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:311)
	at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:120)
	at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1022)
	at org.apache.catalina.core.StandardHost.start(StandardHost.java:736)
	at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1014)
	at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:443)
	at org.apache.catalina.core.StandardService.start(StandardService.java:448)
	at org.apache.catalina.core.StandardServer.start(StandardServer.java:700)
	at org.apache.catalina.startup.Catalina.start(Catalina.java:552)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:295)
	at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:433)
29/09/2011 08:37:48 org.apache.catalina.core.StandardContext start
SEVERE: Error filterStart

Below is my Web.xml is where I think the error is more I can not solve it

Java Code:
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
	http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">

	<display-name>SCG - Sistema de Controle e Gestão v2.0</display-name>

	<context-param>
		<param-name>log4jConfigLocation</param-name>
		<param-value>
			/WEB-INF/classes/log/log4j.properties
		</param-value>
	</context-param>

	<listener>
		<listener-class>
			org.springframework.web.util.IntrospectorCleanupListener</listener-class>
	</listener>

	<listener>
		<listener-class>org.springframework.web.util.Log4jConfigListener</listener-class>
	</listener>

	<listener>
		<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
	</listener>

	<listener>
		<listener-class>
			org.springframework.web.context.request.RequestContextListener</listener-class>
	</listener>

	<listener>
		<listener-class>
			org.springframework.security.ui.session.HttpSessionEventPublisher</listener-class>
	</listener>

	<!--
		Arquivos de Configuracao de Contexto do Spring e tambem da Seguranca
	-->
	<context-param>
		<param-name>contextConfigLocation</param-name>
		<param-value>
			/WEB-INF/classes/spring/applicationContext.xml
		</param-value>
	</context-param>

	<filter> 
		<filter-name>struts-cleanup</filter-name> 
		<filter-class>org.apache.struts2.dispatcher.ActionContextCleanUp</filter-class> 
	</filter> 

	<filter-mapping>
		<filter-name>struts-cleanup</filter-name>
		<url-pattern>/*</url-pattern>
	</filter-mapping>

	<filter>
		<filter-name>Struts2DispatcherFilter</filter-name>
		<filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter </filter-class>
		<init-param>
			<param-name>config</param-name>
			<param-value>struts-default.xml,struts-plugin.xml,struts/struts.xml</param-value>
		</init-param>
	</filter>

	<filter-mapping>
		<filter-name>Struts2DispatcherFilter</filter-name>
		<url-pattern>/*</url-pattern>
	</filter-mapping>

	

	<!-- Inicializador -->
	<servlet>
		<servlet-name>Inicializador</servlet-name>
		<servlet-class>br.com.cosmo.scg2.servlet.ScgInitServlet</servlet-class>
		<load-on-startup>1</load-on-startup>
	</servlet>

	<servlet>
		<servlet-name>Report</servlet-name>
		<servlet-class>br.com.cosmo.scg2.servlet.RelatoriosServlet</servlet-class>
		<load-on-startup>1</load-on-startup>
	</servlet>

	<servlet>
		<servlet-name>dwr-invoker</servlet-name>
		<description>Direct Web Remoter Servlet</description>
		<servlet-class>org.directwebremoting.servlet.DwrServlet</servlet-class>
		<init-param>
			<param-name>debug</param-name>
			<param-value>true</param-value>
		</init-param>
		<init-param>
			<param-name>activeReverseAjaxEnabled</param-name>
			<param-value>true</param-value>
		</init-param>
		<init-param>
			<param-name>initApplicationScopeCreatorsAtStartup</param-name>
			<param-value>true</param-value>
		</init-param>
		<init-param>
			<param-name>maxWaitAfterWrite</param-name>
			<param-value>100</param-value>
		</init-param>
		<load-on-startup>1</load-on-startup>
	</servlet>

	<servlet-mapping>
		<servlet-name>dwr-invoker</servlet-name>
		<url-pattern>/dwr/*</url-pattern>
	</servlet-mapping>

	<servlet-mapping>
		<servlet-name>Report</servlet-name>
		<url-pattern>/report</url-pattern>
	</servlet-mapping>

	<session-config>
		<session-timeout>30</session-timeout>
	</session-config>

	<error-page>
		<error-code>403</error-code>
		<location>/geral/erros/Erro403-SemPermissaoAcesso.jsp</location>
	</error-page>

	<error-page>
		<error-code>404</error-code>
		<location>/geral/erros/Erro404-PaginaInexistente.jsp</location>
	</error-page>

	<error-page>
		<error-code>500</error-code>
		<location>/geral/erros/visualizadorPadraoErros.jsp</location>
	</error-page>

	<taglib>
		<taglib-uri>/scg2-tags</taglib-uri>
		<taglib-location>/WEB-INF/scg2-app.tld</taglib-location>
	</taglib>

	<welcome-file-list>
		<welcome-file>index.jsp</welcome-file>
	</welcome-file-list>

	<persistence-unit-ref>
		<persistence-unit-ref-name>persistence.xml</persistence-unit-ref-name>
		<persistence-unit-name>JPA_SCG2</persistence-unit-name>
	</persistence-unit-ref>






</web-app>
Personal help me I do not know what to do to fix this error!
Thank you!
I am waiting for your response!