Issue description: i have made a modded server with a few friends and i was setting up a builder to place dirt in a flat plane for a tree farm about half thought placing the dirt then the server crashed. now every time i try to start the server it crashes.

Steps to reproduce:

Versions:

• Minecraft: 1.12.2
• Forge: 14.23.5.2806
• CompatLayer (only if on Minecraft 1.10 or 1.11):
• McJtyLib: 1.12-3.0.7
• RFTools: 1.12-7.59

Possibly incompatible mods and versions:

Relevant logs, if any:
crash-2019-01-04_17.47.32-server.txt

Can you find steps to reproduce the problem in a fresh world, preferably with no other mods installed?

i try to reproduce it but i had no luck

I'm guessing that the problem is with another mod then. See if you can find out which one by doing a binary search.

ok. i will try that later

ok i just found a way to recreate the crash

step 1: take some tinkers construct glow balls and place some down
step 2: have the build place chest where the glow balls are
step 3: crash

i found this out when looking at the world in mcedit and i notice i put chests inside the chest on top of the builder and i notice it stopped placing them at the glow ball and that where the server crashed

EDIT:
i do think part of the problem is the chest can be placed by a builder. chest can get very buggy when you have 3 or more chest in a row