Broken Tag Fixer

Broken Tag Fixer silences the dreaded warning:

[Mekanism] Broken tags in Mekanism recipes detected

…and the whole class of problems behind it — empty item tags that recipes still reference.

It is generic: it is not tied to Mekanism. It works for any mod whose recipes point at an item tag that ended up empty (very common with optional cross-mod "compat" recipes, e.g. Ad Astra shipping a recipe but not the matching tag).

The problem

A mod ships a recipe that uses an item tag (for example forge:sandstone/venus_sandstone), but nothing ever fills that tag — the item exists, the recipe loads, yet the tag is empty. Minecraft/Mekanism then complain that the recipe has a broken ingredient, spamming your log on every launch.

What it does

At load time, Broken Tag Fixer scans every recipe of every mod (raw JSON, no mod API needed) and, for each empty tag a live recipe depends on, it applies a careful cascade:

Known-fix table — a deterministic mapping for cases that are already understood.
Smart scoring — if there's no known fix, it scores every registered item against the tag using several signals (material coverage, exact name, "form" word like ingot/dust/gem, the recipe's own context/namespace…) and fills the tag only when it is highly confident.
Clean disable — if the tag truly cannot be resolved, the offending recipe is removed before Mekanism (or anyone) sees a broken ingredient. No more warning, no crash.

Built to be safe

This mod is intentionally conservative — it never "guesses wildly":

Condition-aware: recipes disabled by a false condition (e.g. mod_loaded) are never touched. Many empty tags are intentional optional-compat — those are left alone.
High-confidence only: a tag is auto-filled only above a strict confidence threshold. Anything below becomes a suggestion in the report, never a silent change.
Fully auditable: every action (fills, disables, suggestions, skipped) is written to brokentagfixer-report.txt in your game directory, so you can see exactly what was done and why.
Fail-safe: if anything goes wrong, it logs and steps aside — it will never break your game's startup.

Compatibility

Forge — Minecraft 1.20.1
NeoForge — Minecraft 1.21.1

Works on both client and server (recommended on both for a multiplayer setup). Lightweight, no config required to get the default safe behaviour.

Install

Drop the matching file into your mods/ folder:

brokentagfixer-forge-1.0.0.jar → Minecraft 1.20.1 (Forge)
brokentagfixer-neoforge-1.0.0.jar → Minecraft 1.21.1 (NeoForge)

Then launch as usual and (optionally) read brokentagfixer-report.txt.

Modpack authors & data contributors

Broken Tag Fixer is data-friendly. If you'd like a specific case added to the built-in known-fix table, or you want to contribute a data-only fix (a tag → item mapping for a particular mod), come tell us on Discord.