Convert a Bukkit/Paper World Back to Vanilla / Fabric

The Difference

Vanilla / Fabric keeps all dimensions inside one world folder:

world/
  region/          ← overworld
  DIM-1/region/    ← nether
  DIM1/region/     ← end

Bukkit / Paper splits them into separate folders:

world/             ← overworld only
world_nether/
  DIM-1/region/
world_the_end/
  DIM1/region/

If you take a Bukkit world to Vanilla/Fabric as-is, only the overworld loads. Nether and End are gone.

Merge The Dimensions Back

1. 1SFTP into the server, download world/, world_nether/, and world_the_end/
2. 2Open world_nether/, copy the DIM-1 folder
3. 3Paste DIM-1 inside the world/ folder
4. 4Open world_the_end/, copy the DIM1 folder
5. 5Paste DIM1 inside the world/ folder
6. 6world/ now has region/, DIM-1/, DIM1/, that's a Vanilla layout

Upload world/ to the Vanilla/Fabric server, start, you're done.

Other Direction (Vanilla → Bukkit)

Bukkit accepts a Vanilla world directly. On first start it'll create empty world_nether/ and world_the_end/ folders. To carry over Nether/End data, copy DIM-1 into world_nether/ and DIM1 into world_the_end/ before the first start.

Need More Help?

Players reporting missing builds in the Nether? Confirm the DIM-1 folder is at the root of the new world, not nested. Ask in Discord if you're stuck.