@earnaud over on ropensci/EML#330 reported seeing a unit with the id molePerKilogram twice in the units list but with slightly different attributes. You can see it's defined twice:

The first time, it's grouped with <!--amountOfSubstanceWeight--> and the second time it's grouped with <!--amountPerMass-->.

It's also listed twice in the eml-unitTypeDefinitions.xsd file:

@mbjones, @mobb: Does this seem like a mistake to you too?

@earnaud also indicates there were other issues but I haven't figured out what those are just yet.

Once fixed, we need to issue a re-release of EML and emld. emld is where the schema files are shipped.