title: What should I do for this NoClassDefFoundError?
body: <pre><code>INFO: validateJarFile(C:\Users\smart\workspace\.metadata\.plugins\org.eclipse.wst.server.core\tmp0\wtpwebapps\ konzernauto1\WEB-INF\lib\servlet-api.jar) - jar not loaded. See Servlet Spec 2.3, section 9.7.2. Offending class: javax/servlet/Servlet.class
  Feb 10, 2014 12:40:20 PM org.apache.catalina.core.StandardContext filterStart
  SEVERE: Exception starting filter struts2
  java.lang.NoClassDefFoundError: com/opensymphony/xwork2/config/FileManagerProvider
      at org.apache.struts2.dispatcher.Dispatcher.init_FileManager(Dispatcher.java:352)
      at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:481)
      at org.apache.struts2.dispatcher.FilterDispatcher.init(FilterDispatcher.java:193)
      at org.apache.catalina.core.ApplicationFilterConfig.initFilter(ApplicationFilterConfig.java:281)
      at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:262)
      at org.apache.catalina.core.ApplicationFilterConfig.&lt;init&gt;(ApplicationFilterConfig.java:107)
      at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:4746)
      at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5399)
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
      at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559)
      at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549)
      at java.util.concurrent.FutureTask.run(Unknown Source)
      at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
      at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
      at java.lang.Thread.run(Unknown Source)
  Caused by: java.lang.ClassNotFoundException: com.opensymphony.xwork2.config.FileManagerProvider
      at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1714)
      at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1559)
      ... 15 more
  </code></pre>