MC - 1.10.2
Loottweaker - 0.0.1
Initial Inventory - 1.0.1
Forge - 12.18.3.220.2
Pastebin - http://pastebin.com/V6YCVKTF

I have added loottweaker to modpack and it crashed. By checking i have found that crash caused by these two mods - Loottweaker and Initial Inventory

@leviathan143 Loottweaker needs to check if the world has loaded before it does its stuff, I have a few mods that reload Crafttweaker before the world has loaded (preinit, init stuff), so they all crash with this).
A simple

if(world !=null)

should do it

@bontavi Sorry about leaving this for so long, github didn't notify me about it until Jared directly pinged me. It's a simple fix, so it won't take long.