As the title says, whenever I try to start a world with both mods installed, it just gets stuck at 100%. There is not crashlog so I can just upload latest.log
I am using this fork of Lithium: https://github.com/AeiouEnigma/lithium-forge/releases

It worked, thank you so much! I'll leave the issue open in case something can be done so both mods' optimizations can work in tandem. If not feel free to close it

Try to paste this in to lithiums's config file.

mixin.world.chunk_access=false
mixin.world.tick_scheduler=false
mixin.alloc.chunk_ticking=false
mixin.world.block_entity_ticking=false
mixin.alloc.chunk_random=false
mixin.chunk.count_oversized_blocks=false