When using the /enchant
command, it uses string ids for enchanting the current held item; for example:
/enchant @p minecraft:efficiency 3
However, the ench NBT tag still uses the old numerical ids; for example, this doesn't give efficiency, but instead gives protection:
/give @p minecraft:diamond_pickaxe 1 0 {ench:[{id:"minecraft:efficiency",lvl:3s}]}
WAI for now: MC-61041