Some JPZs (e.g. https://crosswordnexus.com/downloads/airout.jpz) have a root tag that doesn't match the schema; the XML parser we are using is strict and refuses to parse in this case. (At least one way this is possible is if you open and save the JPZ using XWord 0.7.0; not sure if there are others. This is fixed in the latest XWord, but hasn't been publicly released yet).
Ideally, we'd just ignore the schema when parsing altogether as it's not particularly meaningful, though we should continue to write the correct one.
Some JPZs (e.g. https://crosswordnexus.com/downloads/airout.jpz) have a root tag that doesn't match the schema; the XML parser we are using is strict and refuses to parse in this case. (At least one way this is possible is if you open and save the JPZ using XWord 0.7.0; not sure if there are others. This is fixed in the latest XWord, but hasn't been publicly released yet).
Ideally, we'd just ignore the schema when parsing altogether as it's not particularly meaningful, though we should continue to write the correct one.