Sterilization Fixer

⚠️ This mod is currently in beta. Bugs, incomplete cleanup behavior, or unexpected issues may occur, so always back up your world before using it.

Sterilization Fixer is a server-side NeoForge utility mod that automatically detects and cleans broken world data left behind by removed or updated mods.

When a mod is removed, existing chunks can still contain references to blocks, entities, block entities, or scheduled ticks that no longer exist. This can cause errors such as:

Unknown registry key in ResourceKey[minecraft:root / minecraft:block]

Sterilization Fixer detects those invalid registry references while the world is loading and safely removes them.

What it fixes

• Missing or orphaned blocks → replaced with air
• Missing block entities → removed
• Missing entities → removed
• Invalid scheduled block ticks → removed
• Invalid scheduled fluid ticks → removed
• Automatically detects broken registry entries
• No need to specify which mod was removed

Automatic cleanup

There are no commands required.

Simply install the mod on the server and start it normally. As affected chunks are loaded, Sterilization Fixer checks their saved data against the registries currently available on the server.

Valid content is left untouched.

Broken content is cleaned automatically and the repaired chunk can then be saved normally.

Example

If a removed mod previously added:

examplemod:machine
examplemod:copper_ore

and those blocks are still present in your world, Sterilization Fixer will detect that the block IDs no longer exist and replace them with:

minecraft:air

No manual block list or removed-mod configuration is required.

Server-side only

Sterilization Fixer is designed as a server-side utility mod.

Players do not need to install it on their clients.

Performance

Sterilization Fixer only processes world data as it is loaded. It does not force-load or regenerate your entire world.

The cleaner is designed to work efficiently on large and heavily modded servers, including servers using asynchronous chunk-loading optimizations.

Important

Back up your world before using any world-repair utility.

Sterilization Fixer intentionally removes content whose registry entries no longer exist. Once cleaned and saved, that removed mod content cannot be restored without reverting to a backup.

Compatibility

• Minecraft: 1.21.1
• Loader: NeoForge
• Environment: Server-side

Sterilization Fixer is intended for servers that frequently add, remove, or update mods and need a safer way to clean orphaned world data without manually hunting down every broken block or entity.