Biomes O' Plenty Crash Fixes: Common Errors Explained

Most Biomes O' Plenty problems are not bugs in the mod. They are mismatches: a missing library, a file for the wrong loader, or a version that does not line up. Working through the checks below in order solves the large majority of cases.

Read the log first

When a modded game fails to start, the loader usually explains why. Look in your Minecraft folder for logs/latest.log and, after a crash, for a new file in the crash-reports folder. Search for lines containing "missing", "requires" or "incompatible". Loaders like Forge, NeoForge and Fabric often show a readable error screen naming the exact mod and version they expected.

Missing dependency errors

If the error names TerraBlender, GlitchCore or Fabric API, one of the required libraries is absent or the wrong version:

TerraBlender is required for Minecraft 1.18 and above.
GlitchCore is required for 1.20.4 and above, and for 1.20.1 from mod version 19.0.0.91 (details in the 1.20.1 guide).
Fabric API is required when you use the Fabric build.

Download the missing library for the same Minecraft version and loader, put it in mods, and launch again.

Wrong loader or version

A Forge jar in a Fabric setup, or a 1.21 jar in a 1.20.1 setup, will not load. Check the file name and the release page for each jar in your mods folder. Remove duplicates too: two different versions of TerraBlender side by side can produce confusing errors.

Java runtime problems

Each Minecraft generation expects a particular Java version. 1.12.2 expects Java 8; 1.18 to 1.20.4 run on Java 17; 1.20.5 and newer need Java 21 or later. The official launcher handles this automatically, but third-party launchers and dedicated servers sometimes point to the wrong runtime. An error mentioning "class file version" or "unsupported major.minor version" almost always means the Java version is wrong.

The game loads but no biomes appear

Old chunks. Only newly generated chunks get the new biomes. Explore far from where you have already been, or make a new world.
Old versions and world types. On 1.17 and below you must create the world with the Biomes O' Plenty world type.
Servers on old versions. 1.15 to 1.17 servers need level-type=biomesoplenty; 1.12.2 and older need level-type=BIOMESOP. From 1.18 onward, no change to server.properties is required.
Configuration changes. If you or a modpack edited files under config/biomesoplenty, some biomes may have been switched off. Try a fresh test world with default configuration.

Use the commands in our biome-finding guide to confirm whether a biome is generating at all.

Isolating a conflict

If the dependencies are right and the game still crashes, another mod may be conflicting. Make a copy of your mods folder, then remove half of the non-essential mods and test. Keep halving until the crash disappears; the last group you removed contains the culprit. It is slower than guessing, but it always finds the answer. When you report a bug to any mod developer, include the full log and your exact versions.