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LexForgeFix

Allow some mods for MinecraftForge 47.3.10+ run on NeoForge 47.1.x

NeoForge
Loaders
NeoForge
Downloads on Modrinth
855
Followers on Modrinth
1
versions
2
Updated
January 7, 2026Jan 7
Published
in 2026

At a glance

Runs on NeoForge
For Minecraft 1.20.1
Needed in the game and on the server
Latest version — 0.1.1 from January 7, 2026
License MIT — free
Where it's needed
In gamerequiredOn serverrequired

Needed both in the game and on the server

Game versions1.20.1

MinecraftForge 1.20.1-47.3.10 introduced a new feature: allowing the mod entry class constructor to obtain an FMLJavaModLoadingContext as a parameter, whereas NeoForge 47.1.x at the same time did not support such a mod constructor.

This mod adds the classic parameterless constructor to these mods through bytecode modifications.

Fix these errors:

-- Head --
Thread: Render thread
Stacktrace:
    at net.minecraftforge.fml.javafmlmod.FMLModContainer.constructMod(FMLModContainer.java:109) ~[language-java-47.2.2.jar%23416!/:47.2] {}
-- MOD somemod --
Details:
    Mod File: <.minecraft>/mods/<somemod>-1.20.1-Forge.jar
    Failure message: Some Mod (somemod) has failed to load correctly
        java.lang.RuntimeException: Could not find mod constructor. Allowed optional argument classes: ModContainer, IEventBus, FMLModContainer
    Mod Version: 1.1.4514
    Mod Issue URL: https://example.com/
    Exception message: java.lang.RuntimeException: Could not find mod constructor. Allowed optional argument classes: ModContainer, IEventBus, FMLModContainer
Stacktrace:
    at net.minecraftforge.fml.javafmlmod.FMLModContainer.constructMod(FMLModContainer.java:109) ~[language-java-47.2.2.jar%23416!/:47.2] {}
    at net.minecraftforge.fml.ModContainer.lambda$buildTransitionHandler$10(ModContainer.java:123) ~[core-47.2.2.jar%23415!/:47.2] {re:mixin}
    at java.util.concurrent.CompletableFuture$AsyncRun.run(CompletableFuture.java:1804) ~[?:?] {}
    at java.util.concurrent.CompletableFuture$AsyncRun.exec(CompletableFuture.java:1796) ~[?:?] {}
    at java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:387) ~[?:?] {}
    at java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1312) ~[?:?] {}
    at java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1843) ~[?:?] {re:mixin,re:computing_frames}
    at java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1808) ~[?:?] {re:mixin,re:computing_frames}
    at java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:188) ~[?:?] {re:mixin}
-- Head --
Thread: Render thread
Stacktrace:
    at java.lang.Class.getConstructor0(Class.java:3761) ~[?:?] {}
-- MOD somemod --
Details:
    Mod File: <.minecraft>/mods/<somemod>-1.20.1-Forge.jar
    Failure message: Some Mod (somemod) has failed to load correctly
        java.lang.NoSuchMethodException: com.example.SomeMod.<init>()
    Mod Version: 0.1.0
    Mod Issue URL: NOT PROVIDED
    Exception message: java.lang.NoSuchMethodException: com.example.SomeMod.<init>()
Stacktrace:
    at java.lang.Class.getConstructor0(Class.java:3761) ~[?:?] {}
    at java.lang.Class.getDeclaredConstructor(Class.java:2930) ~[?:?] {}
    at net.minecraftforge.fml.javafmlmod.FMLModContainer.constructMod(FMLModContainer.java:68) ~[javafmllanguage-1.20.1-47.1.3.jar%23181!/:?] {}
    at net.minecraftforge.fml.ModContainer.lambda$buildTransitionHandler$10(ModContainer.java:123) ~[fmlcore-1.20.1-47.1.3.jar%23180!/:?] {}
    at java.util.concurrent.CompletableFuture$AsyncRun.run(CompletableFuture.java:1804) ~[?:?] {}
    at java.util.concurrent.CompletableFuture$AsyncRun.exec(CompletableFuture.java:1796) ~[?:?] {}
    at java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:387) ~[?:?] {}
    at java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1312) ~[?:?] {}
    at java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1843) ~[?:?] {}
    at java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1808) ~[?:?] {}
    at java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:188) ~[?:?] {}

FAQ

How to install LexForgeFix?

Install NeoForge for your Minecraft version, download LexForgeFix for the same version and loader, put the file into the mods folder and launch the game with the loader profile.

Which Minecraft versions does LexForgeFix support?

LexForgeFix has builds for Minecraft 1.20.1.

Is LexForgeFix needed on the server?

Needed in the game and on the server

License and source
MIT Licensefree to use and share with credit to the author
Original — Modrinth↗Files unchanged, verified with SHA-512Is this your mod? For rights holders

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