<error-page/> entries in web.xml for paths defined by servlet-mapping tags other than the FacesServlet are marked as errors: location does not exists.

Hier a example:
.....
<servlet-mapping>
<servlet-name>Faces Servlet</servlet-name>
<url-pattern>*.faces</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>ErrorRedirectServlet</servlet-name>
<url-pattern>/ErrorRedirect</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>TimeOutServlet</servlet-name>
<url-pattern>/TimeOut</url-pattern>
</servlet-mapping>
.......
<error-page>
<exception-type>javax.faces.application.ViewExpiredException</exception-type>
<location>/TimeOut</location>
</error-page>
<error-page>
<error-code>500</error-code>
<location>/ErrorRedirect</location>
</error-page>
<error-page>
<error-code>403</error-code>
<location>/ErrorRedirect</location>
</error-page>

<error-page> tags are marked as errors.