https://gist.github.com/ProsperCraft/d7ec71cd0e1ed87449476b05afeb2a96

Futurepack-1.12.2-26.3.123

As I am only calling func_175698_g (sewtBLockToAir) this issue can not be mine, it is a mssing CLass Excpetion in a Vanilla class, so you should check if you updated your coremods.

CTMCorePlugin (CTM-MC1.12-0.2.3.12.jar)
FarseekCoreMod (Farseek-1.12-2.2.3.jar)
Techguns Core (techguns-1.12.2-2.0.1.1.jar)
Plugin (NotEnoughIDs-1.5.4.2.jar)
Wizardry Plugin (wizardry-0.7.2.jar)
LoadingPlugin (noRecipeBook_v1.1.0formc1.12.2.jar)
OpenEyePlugin (OpenEye-1.12.1-0.8.jar)
RandomPatches (randompatches-1.12.2-1.0.1.0.jar)
ShetiPhian-ASM (shetiphiancore-1.12.0-3.5.6.jar)
IELoadingPlugin (ImmersiveEngineering-0.12-77-core.jar)
Inventory Tweaks Coremod (InventoryTweaks-1.64-dev.jar)
ForgelinPlugin (Forgelin-1.6.0.jar)
LoadingPlugin (ResourceLoader-MC1.12.1-1.5.3.jar)
TransformerLoader (OpenComputers-MC1.12.1-1.7.1.43.jar)
Born in a Barn (Born In A Barn V1.8-1.12-1.0.jar)
LibrarianLib Plugin (librarianlib-1.12.2-4.7.jar)
LoadingPlugin (NoNausea-MC1.12-1.0.jar)
CoreModLoader (applied-llamagistics-1.12.1-rv5-beta-10.jar)
BCModPlugin (backpacks 1.12.2 - 3.4.3.jar)