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Unsafe World Random Access Detector
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Unsafe World Random Access Detector

by ishland · on Modrinth

This is a mod that detects unsafe off-thread world random access, helping to find causes of "Accessing LegacyRandomSource from multiple threads" crash.

Which build do you need?

This mod ships a separate file for every mod loader and every version of the game. Pick both, then download — the wrong build installs fine and then does nothing in the game.

Mod loader

Minecraft version

⬇ Download for 26.1–26.2 · Fabric⬇ Download for 1.19.4–1.21.11 · Fabric⬇ Download for 1.21–1.21.5 · NeoForge⬇ Download for 1.20.6–1.21.1 · Forge⬇ Download for 1.19.3–1.20.4 · Forge
I don't know my version or loader
Open the Minecraft launcher and look at the profile you play on — it names both, like fabric-loader-1.21.4. The version also shows in the bottom-right corner of the game's main menu.
No loader in the profile name? Then it's plain Minecraft, and these mods won't run — you need Fabric or NeoForge installed first.
Open in MC Java ModsGet it on Google Play →
Unsafe World Random Access Detector — screenshot 1

Unsafe World Random Access Detector

This is a mod that detects unsafe off-thread world random access, helping to find causes of "Accessing LegacyRandomSource from multiple threads" crash.

This is useful for finding the cause of mysterious crashes with Accessing LegacyRandomSource from multiple threads.
This is not a fix for the issue, but it will help you find the cause of the issue.

Example

Note: If you are already using C2ME, this mod is not needed (but won't crash if used together anyway).

Quick facts

Install steps are the general flow for this file type — How to install Minecraft Java mods & modpacks walks through it step by step.

Verified by MCModsHub

These come from our own check of the pack file, not from the source page.

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