Access Transformer Fix

Restore Access Transformers. Eliminate Access Errors.

Access Transformer Fix is a compatibility utility for NeoForge modpacks that restores missing or incorrectly applied Access Transformer (AT) changes at runtime.

Large modpacks occasionally encounter situations where classes are loaded without all required access transformations. The result can be seemingly random crashes such as:

• IllegalAccessError
• inaccessible Minecraft methods or fields
• GUI rendering crashes
• inventory screen failures
• incompatibilities between otherwise compatible mods

Instead of patching individual mods, Access Transformer Fix automatically discovers and merges Access Transformer definitions from installed mods to recover the intended access levels.

Features

• Automatically scans installed mods for META-INF/accesstransformer.cfg
• Detects and merges access rules from multiple mods
• Resolves conflicting access levels by applying the widest required visibility
• Generates detailed diagnostic reports for troubleshooting
• Designed to work with any NeoForge modpack
• No configuration required

Conflict Resolution

If multiple mods request different access levels for the same class member, Access Transformer Fix always applies the widest visibility required.

Example:

Mod A:
protected findSlot(...)

Mod B:
public findSlot(...)

Result:
public findSlot(...)

This guarantees that every mod receives at least the level of access it requires.

Diagnostics

The mod generates detailed reports inside the logs directory, allowing modpack authors to inspect discovered Access Transformers, merged rules, and detected conflicts.

These reports make diagnosing compatibility issues significantly easier than relying solely on crash logs.

Intended Use

This mod is intended for:

• large NeoForge modpacks
• compatibility testing
• debugging Access Transformer issues
• recovering from loader inconsistencies
• identifying conflicting Access Transformer definitions

Compatibility

Designed for NeoForge 1.21.1.

The mod performs no gameplay changes and is safe to include in both client and server environments unless a compatibility issue is explicitly identified.