- Loaders
- NeoForge
- Downloads on Modrinth
- 855
- Followers on Modrinth
- 1
- versions
- 2
- Updated
- January 7, 2026Jan 7
- Published
- in 2026
At a glance
Needed both in the game and on the server
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