application [irj] Processing HTTP request to servlet [gateway] finished with error

Hi Experts,

I had done System copy on below enviornment

OS: Windows 2008server

DB: Ora11g

NW: 7.01

Everythimg went smooth. System is in GREEN status but getting error to open irj/portal,

500   Internal Server Error
		SAP J2EE Engine

  java.lang.NullPointerException: null
 Exception id: [005056BC6B170073000000020000130000051887CDCBDE11]

I can able to open NWA, can launch Visual admin, etc.. all other links except irj/portal

Error log file:

application [irj] Processing HTTP request to servlet [gateway] finished with error. The error is: java.lang.NullPointerException

  at com.sap.portal.navigation.Gateway.service(Gateway.java:117)

  at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)

  at com.sap.engine.services.servlets_jsp.server.HttpHandlerImpl.runServlet(HttpHandlerImpl.java:401)

  at com.sap.engine.services.servlets_jsp.server.HttpHandlerImpl.handleRequest(HttpHandlerImpl.java:266)

  at com.sap.engine.services.httpserver.server.RequestAnalizer.startServlet(RequestAnalizer.java:386)

  at com.sap.engine.services.httpserver.server.RequestAnalizer.startServlet(RequestAnalizer.java:364)

  at com.sap.engine.services.httpserver.server.RequestAnalizer.invokeWebContainer(RequestAnalizer.java:1060)

  at com.sap.engine.services.httpserver.server.RequestAnalizer.handle(RequestAnalizer.java:265)

  at com.sap.engine.services.httpserver.server.Client.handle(Client.java:95)

  at com.sap.engine.services.httpserver.server.Processor.request(Processor.java:175)

  at com.sap.engine.core.service630.context.cluster.session.ApplicationSessionMessageListener.process(ApplicationSessionMessageListener.java:33)

  at com.sap.engine.core.cluster.impl6.session.MessageRunner.run(MessageRunner.java:41)

  at com.sap.engine.core.thread.impl3.ActionObject.run(ActionObject.java:37)

  at java.security.AccessController.doPrivileged(Native Method)

  at com.sap.engine.core.thread.impl3.SingleThread.execute(SingleThread.java:104)

  at com.sap.engine.core.thread.impl3.SingleThread.run(SingleThread.java:176)

Pls suggest any work arounds.

Thanks in advance.

Regards,

Sayendra.M