Title. Here's what my config looks like for the Emblem of Monster Slayer:
# Whether or not Emblem of Monster Slayer should provide +1 Looting Level. [default: true, synchronized: yes]
B:MonsterCharmBonusLooting=false

# Whether or not Emblem of Monster Slayer should provide double experience drop from monsters. [default: true, synchronized: yes]
B:MonsterCharmDoubleXP=true

# Damage bonus against agressive creatures for Emblem of Monster Slayer. Defined as percentage. [range: 0 ~ 1000, default: 10, synchronized: yes]
I:MonsterCharmHostileDamage=0

# Damage bonus against undead enemies for Emblem of Monster Slayer. Defined as percentage. [range: 0 ~ 1000, default: 25, synchronized: yes]
I:MonsterCharmUndeadDamage=0

here's the error, only shows up if I try pressing shift while hovering over said charm.

curios version 4.0.2.0
forge version 34.1.0
enigmatic legacy version 2.6.0

Really isn't even because of config alterations, I just misassigned some config objects in item class which causes NullPointerException in a wide variety of situations. Too bad