WDRuntimeException: Exit-Plug must no be triggered

Dear gurus

i am getting this error while in JCo

The initial exception that caused the request to fail, was:

com.sap.tc.webdynpro.services.exceptions.WDRuntimeException: Exit-Plug must no be triggered with an URL when running in portal. Use portal navigation instead to navigate to another application!

at com.sap.tc.webdynpro.progmodel.view.View.navigate(View.java:516)

at com.sap.tc.webdynpro.progmodel.view.View.navigate(View.java:462)

at com.sap.sld.wd.main.wdp.InternalMainInterfaceView.wdFirePlugToOldUI(InternalMainInterfaceView.java:154)

at com.sap.sld.wd.main.Head.onActionAdministration(Head.java:277)

at com.sap.sld.wd.main.wdp.InternalHead.wdInvokeEventHandler(InternalHead.java:227)

... 29 more

Any help

Thanks and Regards