Cannot find FacesContext

Front-end
#1

Pessoal,

  Estou fazendo meu primeiro exemplo utilizando jsf, e estou com um probleminha.

seguinte, estou conseguindo acessar a página jsf pela url http://localhost:8080/coreJavaServerFaces/com/capituloUm/index.jsf
porém, ela não passa para a página seguinte, quando se clica no h:commandButton, gera a seguinte exceção: Cannot find FacesContext.
Não está navegando, permenece na mesma página.

segue configuração do web.xml :

<?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>coreJavaServerFaces</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
  
<servlet>
    <servlet-name>Faces Servlet</servlet-name>
    <servlet-class>javax.faces.webapp.FacesServlet</servlet-class>
    <load-on-startup>1</load-on-startup>
</servlet>

<servlet-mapping>
    <servlet-name>Faces Servlet</servlet-name>
    <url-pattern>*.jsf</url-pattern>
</servlet-mapping>
</web-app>

faces-config.xml :

<faces-config
    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-facesconfig_1_2.xsd"
    version="1.2">

	<navigation-rule>
      <from-view-id>/index.jsp</from-view-id>
      <navigation-case>
         <from-outcome>login</from-outcome>
         <to-view-id>/welcome.jsp</to-view-id>
      </navigation-case>
   </navigation-rule>

   <managed-bean> 
      <managed-bean-name>user</managed-bean-name>
      <managed-bean-class>com.capituloUm.UserBean</managed-bean-class> 
      <managed-bean-scope>session</managed-bean-scope> 
   </managed-bean>
</faces-config>
#2