chain.doFilter(req, resp); is throwing a null pointer exception

[liorza]

Can anyone please explain what are potential reasons for receiving Null pointer exception from
Chain.do(…) call (within a filter)

I have two filters that are defined in my web.xml

<filter>
		<filter-name>HibernatePersistence</filter-name>
		<display-name>HibernatePersistence</display-name>
		<filter-class>
			com.regence.mxp.servlet.filter.HibernatePersistence
		</filter-class>
	</filter>
	<filter>
		<filter-name>WebPerformanceLogging</filter-name>
		<display-name>WebPerformanceLogging</display-name>
		<description>Web page performance logger</description>
		<filter-class>
			com.regence.mxp.web.filter.WebPerformanceLogginFilter
		</filter-class>
	</filter>
	<filter-mapping>
		<filter-name>HibernatePersistence</filter-name>
		<url-pattern>/*</url-pattern>
	</filter-mapping>
	<filter-mapping>
		<filter-name>WebPerformanceLogging</filter-name>
		<url-pattern>*.do</url-pattern>
	</filter-mapping>
	<filter-mapping>
		<filter-name>WebPerformanceLogging</filter-name>
		<url-pattern>*.html</url-pattern>
	</filter-mapping>
	<filter-mapping>
		<filter-name>WebPerformanceLogging</filter-name>
		<url-pattern>*.jsp</url-pattern>
	</filter-mapping>
	<filter-mapping>
		<filter-name>WebPerformanceLogging</filter-name>
		<url-pattern>*.htm</url-pattern>
	</filter-mapping>

When the second filter (WebPerformanceLogging) is calling the chain.do(…) I am getting back

12:671 PDT] 6943e414 WebGroup      E SRVE0026E: [Servlet Error]-[]: java.lang.NullPointerException
	at org.apache.struts.action.RequestProcessor.processForwardConfig(RequestProcessor.java:441)
	at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:279)
	at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1482)
	at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:525)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:760)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
	at com.ibm.ws.webcontainer.servlet.StrictServletInstance.doService(StrictServletInstance.java:110)
	at com.ibm.ws.webcontainer.servlet.StrictLifecycleServlet._service(StrictLifecycleServlet.java:174)
	at com.ibm.ws.webcontainer.servlet.IdleServletState.service(StrictLifecycleServlet.java:313)
	at com.ibm.ws.webcontainer.servlet.StrictLifecycleServlet.service(StrictLifecycleServlet.java:116)
	at com.ibm.ws.webcontainer.servlet.ServletInstance.service(ServletInstance.java:283)
	at com.ibm.ws.webcontainer.servlet.ValidServletReferenceState.dispatch(ValidServletReferenceState.java:42)
	at com.ibm.ws.webcontainer.servlet.ServletInstanceReference.dispatch(ServletInstanceReference.java:40)
	at com.ibm.ws.webcontainer.filter.WebAppFilterChain.doFilter(WebAppFilterChain.java:76)

Thanks Lior