There are two XSD files (which has been a source of confusion in the past), but the one which the JAXB models are based upon is in
src/main/resources/org.hibernate/xsd/mapping/legacy-mapping-4.0.xsd

Anyway, in that XSD, you'll notice the RootEntityType has the tuplizer listed before the cache element so technically your your XML does not conform to the expected XSD. Please rearrange your elements and you should be fine.