Typo in /bushes/mod.conf

[A S Lewis]

optional_depends = stonage, sumpf

I think that should be stoneage, especially since init.lua contains the code

biome_lib.register_on_generate({ surface = { "default:dirt_with_grass", "stoneage:grass_with_silex", "sumpf:peat", "sumpf:sumpf" }, rarity = bushes_bush_rarity, rarity_fertility = bushes_bush_rarity_fertility, plantlife_limit = bushes_bush_fertility, min_elevation = 1, -- above sea level }, abstract_bushes.grow_bush )

[OgelGames]

You're correct, thanks 👍