Install Oh The Biomes You'll Go on a server

Oh The Biomes You'll Go, usually called BYG, adds more than 80 new biomes across the Overworld, the Nether and the End. It runs on Forge, Fabric and Quilt, and every player needs it on their own game too.

Checked against Oh The Biomes You'll Go 4.0.1.3 on Forge 1.19.4, October 2026.

Know the version first

The project's GitHub repository is archived, and 4.0.1.3 for Minecraft 1.19.4 is the newest release, uploaded in November 2024. There is no build for 1.20 or later, so a server running this mod stays on 1.19.4.

• Forge on Minecraft 1.19.4. Pick 1.19.4 in JAR Manager and the panel runs the server on Java 17 for you.
• Three libraries. The mod needs TerraBlender 2.2.0.0 or newer, CorgiLib 3.0.0.0 or newer and GeckoLib 4.2 or newer. Modrinth lists all three as required, so the install window offers them.
• Fabric or Quilt instead? The same version has a Fabric and Quilt file. It also needs Fabric API on top of the three libraries.

Switch the server to Forge 1.19.4

1. Open JAR Manager, under More in the left rail.
2. Set Server software to Forge and Minecraft version to 1.19.4, then press Apply change.
3. Leave Take a backup first ticked, press and hold Confirm & reinstall, and wait for the console to finish.

Change your Minecraft version or mod loader covers the switch in full.

Install it

1. Open the Mods tab under Content and leave the Modrinth source chip selected.
2. Search for Oh The Biomes You'll Go and press Install.
3. A window titled "Needs 3 more add-ons" lists TerraBlender, GeckoLib and CorgiLib. Press Install all (4). BYG is about 38 MB, so it takes about 15 seconds to appear in mods, saved as Oh_The_Biomes_Youll_Go-forge-1.19.4-4.0.1.3.jar. Any add-on the panel cannot find a file for is greyed out, so install that one by hand from the Mods tab.
4. Go to Console, press Start and accept the EULA prompt the first time. The server is ready when the console shows Done.

Modrinth only has beta builds of TerraBlender (newest 2.3.0.22) and CorgiLib (3.0.0.0) for 1.19.4. The panel installs the newest beta when a project has no release for your version, so that is expected.

Start a new world

BYG's own wiki says its Nether and End biomes do not show up in an existing world unless you edit the world's level.dat. The simple route is a fresh world. Reset your Minecraft world and start fresh covers it, including keeping the old world on disk.

Change the settings

BYG keeps its settings in a byg folder inside config. The first start fills it with a README.txt, which links to the configs page of BYG's wiki, and these biome files:

• overworld/byg-overworld-biomes.json5 for Overworld biomes.
• nether-biomes.json5 for the Nether.
• end-biomes.json5 for the End.

The same folder also holds settings.json5, trades.json5 and a few more.

Open one in the File Manager, press Save and restart the server.

Common problems

• The server crashes on start. BYG's wiki says to try resetting its configs. Stop the server, delete BYG's settings folder inside config in the File Manager and start again.
• The first start stops with Exit code: 137 and Out of memory: true. The server ran out of memory. In our check on the 1 GB Grass plan the first start did this, then the server restarted by itself and reached Done. If it happens every time, the server needs more memory: our plans list mods from 3 GB. Fix Minecraft Java exit codes explains the code.
• It names TerraBlender, CorgiLib or GeckoLib. Install the missing library from the Mods tab, in the build for 1.19.4.
• Players cannot join. They need the same BYG file and its libraries on Forge 1.19.4. Press Export for players in the Installed view of the Mods tab, then read Join a modded server from your launcher.
• Something else breaks at start. Fix Minecraft mod and plugin load errors walks through reading the log.