Pack version 2.3 & 2.4, running on a server.
Advancements intermittently don’t grant to players. Sometimes re-launching minecraft causes the player to get a bunch of them at once (like the server remembers it has been done), sometimes re-logging does, sometimes nothing helps.
We’ve seen this with vanilla achievements such as getting diamonds, making a potion, return a fireball to a ghast; as well as with mod achievements like from the monk mod, which are required to get the monk levels.
Standard config. We have an FTB utilities starter kit setup, and no other config changes made.