This is not your typical "bug", but...
\worldgen\subworlds\Bottom.yaml, the Magma Biome worldgen file, uses ToxicJungle const leaving the MagmaCore sad and lonely - just something I stumbled onto when I was working on the seed hunting mod doing biome size calculations. It breaks nothing, but I thought I'd let you know!
Keep on rocking
Steps to Reproduce
Ummm open the file :)
This issue has not been confirmed by a developer yet.