Witch's Cauldron causing crashes

[talpidae]

Minecraft version:
1.7.10

Unabridged version:
R13a
(yes, installed update rolled out yesterday)

Issue Description:
Dedicated server is kicking players who are standing or running near a Witch's Cauldron
Players are unable to join again, they get kicked immediately. Tried to remove it ingame, got kicked too.
Will it work, if i remove the Witchery Mod as a temporary fix?

Steps to Reproduce:
Just place a Witch's Cauldron

Crash report or log (uploaded to gist.github.com or pastebin.com):
http://pastebin.com/bdB0Wy3T

[FastQuack]

instead of putting "Latest from AT launcher" please consider putting the actual version: Unabridged R13a

[talpidae]

Sorry, edited!