WEB Dynpro JCO connection problem

Hi ...

I am facing a serious problem while trying to run the Web Dynpro application.

The JCO connections are tested fine while trying from WAS server, but giving the following error when tried to run ...

com.sap.tc.webdynpro.services.exceptions.WDTypeNotFoundException: type extern:com.sap.model.examples.types.IFlightsModel:com.sap.model.examples.types.Bapisfldst could not be loaded: com.sap.dictionary.runtime.DdException: failed to create provider: null

Please help.