validate changes document

[EJ Ciramella]

Hello all - I'd like to leverage the "validate-changes" part of the
maven-changes-plugin, but no matter what I do, I get this:
 
Caused by:
org.apache.maven.plugin.changes.schema.SchemaValidatorException:
SAXException : cvc-elt.1: Cannot find the declaration of element
'document'.
 
Even when clearly it has a "document" element.
 
Any ideas?