title: Tomcat Not starting up> java.lang.ClassNotFoundException: org.apache.catalina.startup.Catalina
body: <p>I am unable to start the tomcat 5.5 server due to following error message in the stderr.log.
  Can someone please help me, it is kind of emergency. Thanks in advance.</p>
  
  <pre><code>java.lang.ClassNotFoundException: org.apache.catalina.startup.Catalina   
  at java.net.URLClassLoader$1.run(URLClassLoader.java:200)   
  at java.security.AccessController.doPrivileged(Native Method)   
  at java.net.URLClassLoader.findClass(URLClassLoader.java:188)   
  at java.lang.ClassLoader.loadClass(ClassLoader.java:306)   
  at java.lang.ClassLoader.loadClass(ClassLoader.java:251)    
  at org.apache.catalina.startup.Bootstrap.init(Bootstrap.java:222)   
  at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:410)    
  </code></pre>