The exception message should be clearer than it is today something like:
"Found no Bean Validation provider: unable to create a ValidatorFactory. Add a provider like Hibernate Validator (RI) to your classpath."
Shouldn't this issue be moved to the BVAL project?
It's actually neither HV nor BVAL but since that was an implementation issue, vie put it here.
Probably worth adding that it would want to be version 4.x (or greater) too.