Mod Ver: 1.6-187
Forge Ver: 2859

Log: https://pastebin.com/cmPfDmTy

When trying to create a world on realistic, the game gets stuck on the 0% screen resulting in me having to manually close the game out. Looking at the log it seems to point at Quark as the problem.

Assuming this is singleplayer world?

Yep, singleplayer.