This is not a bug more a problem which everybody can reproduce, I think.
Steps to reproduce:
- plant a lot of oak trees, at least 10 because it makes it easier to produce the lag
- wait till they are a 1000 years old
- use the harvest tool on the trees and open up the carpenter crafting menu
- when the hearthlings chop down the trees and they wood count is starting to rise the lag will start too.
It seems that the live update of the wood count slows down the game too much.
Version Number and Mods in use:
A20 r701 x64
Yang & co’s Armoury
Hearthlings of Many Faces
Slabs with terrain colors
Settlement Decor Mod