title: Servlet jar not loaded Tomcat Issue
body: <p>I restarted tomcat today and the webapp is offline.</p>
  
  <p>And when I referred catalina.out file I saw the following error.</p>
  
  <pre><code>Dec 27, 2012 6:38:21 AM org.apache.catalina.loader.WebappClassLoader validateJarFile
  INFO: validateJarFile(/dun/stud01/webapps/WEB-INF/lib/servlet.jar) - jar not loaded. See Servlet Spec 2.3, section 9.7.2. Offending class: javax/servlet/Servlet.class
  </code></pre>
  
  <p>All this time before today the appliacation was working fine.
  Its a Unix IBM-AIX server envirnment. </p>
  
  <p>I dont know what went wrong all this time it was working fine.
  Can anyone suggest how to bring back the website online.</p>