It seems the WSDL you're trying to import explicitly imports a schema that defines XSD (the schema at "http://www.w3.org/2001/XMLSchema.xsd"). This is absolutely superfluous, as XSD is recognized automatically when importing a WSDL, and in this case even causes the WSDL to be rejected, due to the presence of a DTD import in the referenced schema. Removing the schema reference from the WSDL should solve this error.