Minecolonies version

version 1.12.2-0.8.8208 (forge 2681)

Expected behavior

• no crash :)

Actual behaviour

• crash

Steps to reproduce the problem

1. will be hard to reproduce since I did many things before (but the world seems to be still corrupted)
2. barracks level 2
   (warning: the zip world file contains rar for better compression)

crash-2018-05-14_09.49.55-client.txt
New World.zip

This issue is also being recreated with the current updated version and the level 3 smelter. Selecting upgrade is causing the crash below.
crash-2018-05-30_01.04.45-client.txt

also fixed.