WDTypeNotFoundException error Jco connection

Hello,

I developed WD project and it was all OK, but when I changed the J2EE engine server host and port to our EP environment, deployed and run I got the following WDTypeNotFoundException error:

com.sap.tc.webdynpro.services.exceptions.WDTypeNotFoundException: type br.com.embraer.dp006.model.zdpnpl098.types.Zz_Doc_Number could not be loaded: com.sap.dictionary.runtime.DdException: TypeBroker failed to access SLD: Error while obtaining JCO connection.

I reimported the model and nothing was changed, I restarted the J2EE server and the error remains. I don't what to do now. Does anybody have a clue? Thanks.