In 18w50a, Villagers no longer have trades by default after specifying NBT data. This was not the case in prior snapshots, when villagers had the Profession tag.
How to reproduce:
- Summon a villager with VillagerData set to
Seems like a useful villager, right?
→ Right click on it, only to be dismayed that the high-ranking villager has absolutely nothing to trade.