Message

Element 'cbc:URI' MUST be provided.

Context
/ubl:DespatchAdvice/cac:DespatchLine/cac:DocumentReference/cac:Attachment/cac:ExternalReference
Test
cbc:URI
Usage
/ ubl:DespatchAdvice / cac:DespatchLine / cac:DocumentReference / cac:Attachment / cac:ExternalReference