Error loading WSDL file in vugen

Hi Forum,

I am having an issue while creating a BPM script in vugen.
When I try to load a WDSL file, I have the following error in the log: "A Locator class was not found in the proxy code. Verify that the WSDL file contains service element(s)."

Did anybody face this problem before? The WSDL file (and its dependent XSD files) look correct, does anybody know what this error means ?

Regards,
Wathek Belhaj Amor