I have a SOAP request :-
I had the same problem and for me schema import didn't work. Stack:
10:18:03,206 | DEBUG | iEsb | DefaultValidationErrorHandler | | 68 - org.apache.camel.camel-core - 2.6.0.fuse-03-01 | Validation error: org.xml.sax.SAXParseException: cvc-elt.1: Cannot find the declaration of element 'soapenv:Envelope'.
org.xml.sax.SAXParseException: cvc-elt.1: Cannot find the declaration of element 'soapenv:Envelope'.
at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.createSAXParseException(ErrorHandlerWrapper.java:233)[:]
My java version was: 1.6.0_45. But I solved it through downloading xsd and importing it as a file:
Maybe it will help somebody.