secure web service, The mysterious and never solve case of the SSL exception

Hello I’m trying to use de SOAP web service connector(6.2.4) to consume a secure service (user and password required) I put all the needed configurations in the connector but I’m receiving this error: PKIX path building failed: unable to find valid certification path to requested target It seems to be the SSL certificate, so I include the server (where the service is running) certificate in the cacert of my jdk and jre, but still don’t work.