Struts

to tentando fazer um exemplo de struts esta dando esse erro no console
java.lang.IllegalArgumentException: Can’t convert argument: null
at org.apache.tomcat.util.IntrospectionUtils.convert(IntrospectionUtils.java:976)
at org.apache.tomcat.util.digester.CallMethodRule.end(CallMethodRule.java:523)
at org.apache.tomcat.util.digester.Rule.end(Rule.java:229)
at org.apache.tomcat.util.digester.Digester.endElement(Digester.java:1058)
at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.endElement(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanEndElement(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown Source)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(Unknown Source)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(Unknown Source)
at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(Unknown Source)
at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(Unknown Source)
at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(Unknown Source)
at org.apache.tomcat.util.digester.Digester.parse(Digester.java:1562)
at org.apache.catalina.startup.ContextConfig.applicationWebConfig(ContextConfig.java:369)
at org.apache.catalina.startup.ContextConfig.start(ContextConfig.java:1062)
at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:261)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:117)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:4239)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045)
at org.apache.catalina.core.StandardHost.start(StandardHost.java:719)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045)
at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:443)
at org.apache.catalina.core.StandardService.start(StandardService.java:516)
at org.apache.catalina.core.StandardServer.start(StandardServer.java:710)
at org.apache.catalina.startup.Catalina.start(Catalina.java:566)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:288)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:413)
21/07/2008 14:38:26 org.apache.catalina.startup.ContextConfig applicationWebConfig
SEVERE: Parse error in application web.xml file at jndi:/localhost/ss/WEB-INF/web.xml
java.lang.IllegalArgumentException: Can’t convert argument: null
at org.apache.tomcat.util.digester.Digester.createSAXException(Digester.java:2726)
at org.apache.tomcat.util.digester.Digester.createSAXException(Digester.java:2752)
at org.apache.tomcat.util.digester.Digester.endElement(Digester.java:1061)
at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.endElement(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanEndElement(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown Source)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(Unknown Source)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(Unknown Source)
at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(Unknown Source)
at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(Unknown Source)
at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(Unknown Source)
at org.apache.tomcat.util.digester.Digester.parse(Digester.java:1562)
at org.apache.catalina.startup.ContextConfig.applicationWebConfig(ContextConfig.java:369)
at org.apache.catalina.startup.ContextConfig.start(ContextConfig.java:1062)
at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:261)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:117)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:4239)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045)
at org.apache.catalina.core.StandardHost.start(StandardHost.java:719)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045)
at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:443)
at org.apache.catalina.core.StandardService.start(StandardService.java:516)
at org.apache.catalina.core.StandardServer.start(StandardServer.java:710)
at org.apache.catalina.startup.Catalina.start(Catalina.java:566)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:288)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:413)
21/07/2008 14:38:26 org.apache.catalina.startup.ContextConfig applicationWebConfig
SEVERE: Occurred at line 12 column 18
21/07/2008 14:38:26 org.apache.catalina.startup.ContextConfig start
SEVERE: Marking this application unavailable due to previous error(s)
21/07/2008 14:38:26 org.apache.catalina.core.StandardContext start
SEVERE: Error getConfigured
21/07/2008 14:38:26 org.apache.catalina.core.StandardContext start
SEVERE: Context [/ss] startup failed due to previous errors
21/07/2008 14:38:26 org.apache.coyote.http11.Http11Protocol start
INFO: Starting Coyote HTTP/1.1 on http-8080
21/07/2008 14:38:26 org.apache.jk.common.ChannelSocket init
INFO: JK: ajp13 listening on /0.0.0.0:8009
21/07/2008 14:38:27 org.apache.jk.server.JkMain start
INFO: Jk running ID=0 time=0/32 config=null
21/07/2008 14:38:27 org.apache.catalina.startup.Catalina start
INFO: Server startup in 650 ms

Só que essa informação é complicado. Tem que olhar o código.

[quote] java.lang.IllegalArgumentException: Can’t convert argument: null
[/quote]

Esse erro acontece qdo o servidor carrega a aplicação ?

Posta aq o seu arquivo web.xml