Could someone please tell me why JBOSS is giving me the following error when launching my application:

11:52:29,729 INFO [STDOUT] 11:52:29,727 ERROR [[/xxxxxx]] Exception starting filter sitemesh
java.lang.NoClassDefFoundError: com/opensymphony/module/sitemesh/filter/PageFilter
  at java.lang.ClassLoader.defineClass1(Native Method)
  at java.lang.ClassLoader.defineClass (ClassLoader.java:620)

This is my web.xml configuration:

 <filter>
    <filter-name>struts2-cleanup</filter-name>
    <filter-class>
       org.apache.struts2.dispatcher.ActionContextCleanup
    </filter-class>
  </filter>
  <filter>
    <filter-name>sitemesh</filter-name>
    <filter-class>
       org.apache.struts2.sitemesh.FreeMarkerPageFilter
    </filter-class>
  </filter>
  <filter>
    <filter-name>struts2</filter-name>
    <filter-class>
       org.apache.struts2.dispatcher.FilterDispatcher
    </filter-class>
  </filter>

<filter-mapping>
  <filter-name>struts2-cleanup</filter-name>
  <url-pattern>/*</url-pattern>
</filter-mapping>
<filter-mapping>
  <filter-name>sitemesh</filter-name>
  <url-pattern>/*</url-pattern>
</filter-mapping>
<filter-mapping>
  <filter-name>struts2</filter-name>
  <url-pattern>/*</url-pattern>
</filter-mapping>

I haven't installed any extra libraries since from my understanding everything is included in the struts package. I have all struts2 libraries loaded from the "all" package.

Hmm, any ideas? I have a feeling I'm missing some sort of configuration?

Regards,
Paul