Nostalrius Begins - Quality wow vanilla realm (1.12)

I tried to run CensusPlus in order to try and which classes are most represented, but it doesn't seem to be able to do its job. Is this on purpose? (Naturally I have a version of the mod that works with 1.12.1)

I'm not talk about uploading data, I simply mean to build a personal database of characters. As I recall the mod uses the /who to figure these things out.