title: java.lang.UnsupportedClassVersionError: Bad version number in .class file error while calling web service
body: <p>I am getting following error while using a web service.</p>
  
  <p>500 Internal Server Error</p>
  
  <pre><code>java.lang.UnsupportedClassVersionError: Bad version number in .class file
      at java.lang.ClassLoader.defineClass1(Native Method)
      at java.lang.ClassLoader.defineClass(ClassLoader.java:620)
      at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:124)
      at com.evermind[Oracle Application Server Containers for J2EE 10g (10.1.2.3.0)].util.OC4JSecureClassLoader.defineClassEntry(OC4JSecureClassLoader.java:172)
      at com.evermind[Oracle Application Server Containers for J2EE 10g (10.1.2.3.0)].naming.ContextClassLoader.defineClass(ContextClassLoader.java:1179)
      at com.evermind[Oracle Application Server Containers for J2EE 10g (10.1.2.3.0)].naming.ContextClassLoader.defineClass(ContextClassLoader.java:1065)
      at com.evermind[Oracle Application Server Containers for J2EE 10g (10.1.2.3.0)].naming.ContextClassLoader.findClass(ContextClassLoader.java:404)
      at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
      at com.evermind[Oracle Application Server Containers for J2EE 10g (10.1.2.3.0)].naming.ContextClassLoader.loadClass(ContextClassLoader.java:143)
      at java.lang.ClassLoader.loadClass(ClassLoader.java:299)
      at com.evermind[Oracle Application Server Containers for J2EE 10g (10.1.2.3.0)].naming.ContextClassLoader.loadClass(ContextClassLoader.java:143)
      at java.lang.ClassLoader.loadClass(ClassLoader.java:299)
      at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
      at oracle.j2ee.ws.JavaRpcWebService.init(JavaRpcWebService.java:85)
      at javax.servlet.GenericServlet.init(GenericServlet.java:258)
      at com.evermind[Oracle Application Server Containers for J2EE 10g (10.1.2.3.0)].server.http.HttpApplication.loadServlet(HttpApplication.java:2358)
      at com.evermind[Oracle Application Server Containers for J2EE 10g (10.1.2.3.0)].server.http.HttpApplication.findServlet(HttpApplication.java:4800)
      at com.evermind[Oracle Application Server Containers for J2EE 10g (10.1.2.3.0)].server.http.HttpApplication.getRequestDispatcher(HttpApplication.java:2826)
      at com.evermind[Oracle Application Server Containers for J2EE 10g (10.1.2.3.0)].server.http.HttpRequestHandler.processRequest(HttpRequestHandler.java:666)
      at com.evermind[Oracle Application Server Containers for J2EE 10g (10.1.2.3.0)].server.http.AJPRequestHandler.run(AJPRequestHandler.java:231)
      at com.evermind[Oracle Application Server Containers for J2EE 10g (10.1.2.3.0)].server.http.AJPRequestHandler.run(AJPRequestHandler.java:136)
      at com.evermind[Oracle Application Server Containers for J2EE 10g (10.1.2.3.0)].util.ReleasableResourcePooledExecutor$MyWorker.run(ReleasableResourcePooledExecutor.java:192)
      at java.lang.Thread.run(Thread.java:595)
  </code></pre>
  
  <p>I have seen earlier posts also but couldn't find any solution for this. The source files are present on a different server and the web service is deployed on different server. Can anyone help to find out what is causing the issue ?</p>