JSR 303 Spec., chapter 4.2. ConstraintViolation: "Bean Validation implementations should ensure that a ConstraintViolation implementation is Serializable provided that the root bean, the leaf bean, the invalid value and keys in the Path object are Serializable objects. If a user wishes to send ConstraintViolation remotely, it should make sure the object graph validated is itself Serializable."
Problem ist: ConstraintViolationImpl currently is not serializable, because ConstraintValidation is not either (and AccessStrategy, Field, Method, all ConstraintValidators are also NOT serializable...)
I think the solution could be to implement methods for serialization/deserialization or, even better, remove field type ConstraintValidation from class ConstraintViolationImpl, so that ConstraintViolationImpl can become serializable.