Erro Jsf

SEVERE: Exception sending context initialized event to listener instance of class com.sun.faces.config.ConfigureListener
com.sun.faces.config.ConfigurationException: CONFIGURATION FAILED! null
...

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

     <context-param>
        <param-name>javax.faces.STATE_SAVING_METHOD</param-name>
        <param-value>client</param-value>
    </context-param>
    <context-param>
        <param-name>com.sun.faces.validateXml</param-name>
        <param-value>true</param-value>
    </context-param>
    <context-param>
        <param-name>com.sun.faces.verifyObjects</param-name>
        <param-value>false</param-value>
    </context-param>

    <!-- RichFaces -->
    <context-param>
        <param-name>org.richfaces.SKIN</param-name>
        <param-value>blueSky</param-value>
    </context-param>
    <!-- RichFaces Filter -->
    <filter> 
        <display-name>RichFaces Filter</display-name> 
        <filter-name>richfaces</filter-name> 
        <filter-class>org.ajax4jsf.Filter</filter-class> 
    </filter>
    <!-- RichFaces Mapping --> 
    <filter-mapping> 
        <filter-name>richfaces</filter-name> 
        <servlet-name>Faces Servlet</servlet-name>
        <dispatcher>REQUEST</dispatcher>
        <dispatcher>FORWARD</dispatcher>
        <dispatcher>INCLUDE</dispatcher>
    </filter-mapping>
    <!-- RichFaces Listener -->
    <listener>
        <listener-class>com.sun.faces.config.ConfigureListener</listener-class>
    </listener>

    <!-- Faces Servlet -->
	<servlet>
		<servlet-name>Faces Servlet</servlet-name>
		<servlet-class>javax.faces.webapp.FacesServlet</servlet-class>
		<load-on-startup>1</load-on-startup>
	</servlet>
	
    <!-- Faces Servlet Mapping -->
	<servlet-mapping>
		<servlet-name>Faces Servlet</servlet-name>
		<url-pattern>*.jsf</url-pattern>
	</servlet-mapping>

	<error-page>
		<error-code>500</error-code>
		<location>/erro.jsp</location>
	</error-page>

	<error-page>
		<error-code>404</error-code>
		<location>/erro.jsp</location>
	</error-page>

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

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

</web-app>