ModsFinder

Unsafe World Random Access Detector

by ishland

With Unsafe World Random Access Detector installed, crashes caused by world random access from multiple threads are caught and reported, helping find the source of the error.

FabricForgeNeoForgeClient or server, optionalMIT LicenseOpen source1.19 – 26.3

What it does

The mod watches for off-thread access to the world's random source, the kind that produces the "Accessing LegacyRandomSource from multiple threads" crash. When such access happens, it reports where it came from, which makes the cause of the crash easier to locate. It is published for Fabric, Forge and NeoForge across 29 release versions, 1.19 – 26.3, and is open source under the MIT License.

Key features

  1. Off-thread access detection

    Flags world random access made from a thread other than the one that owns the world.

  2. Crash cause reporting

    Records where the offending access happened, to help track down the source of the crash.

  3. Snapshot builds

    Builds exist for snapshot releases as well as stable game versions.

Compatibility

Latest build for each game version and loader.

26.x5 of 5 versions with builds
26.31.2.0Not available1.1.4+neoforge
26.21.2.0Not available1.1.4+neoforge
26.1.21.2.0Not available1.1.4+neoforge
26.1.11.2.0Not available1.1.4+neoforge
26.11.2.0Not available1.1.4+neoforge
1.21.x12 of 12 versions with builds
1.21.111.1.4Not available1.1.4+neoforge
1.21.101.1.4Not available1.1.4+neoforge
1.21.91.1.4Not available1.1.4+neoforge
1.21.81.1.4Not available1.1.4+neoforge
1.21.71.1.4Not available1.1.4+neoforge
1.21.61.1.4Not available1.1.4+neoforge
1.21.51.1.4Not available1.1.4+neoforge
1.21.41.1.4Not available1.1.4+neoforge
1.21.31.1.4Not available1.1.4+neoforge
1.21.21.1.4Not available1.1.4+neoforge
1.21.11.1.41.1.1+forge1.1.4+neoforge
1.211.1.41.1.1+forge1.1.4+neoforge
1.20.x7 of 7 versions with builds
1.19.x5 of 5 versions with builds
ReleaseBetaAlphaNot available

This mod also publishes snapshot builds. Snapshots are not shown in the matrix.

Questions

Does the mod need to be installed on a server?

It works on either side, and neither needs it, so it can run on a client, a server, both, or neither.

Which game versions have files?

Files exist for 1.19 – 1.21.11 and for 26.1, 26.1.1, 26.1.2, 26.2 and 26.3, with 1.1.4 for 1.21.11 as the latest Fabric file.

In the catalog

Unsafe World Random Access Detector is one of 36,990 Utility mods on ModsFinder, and one of 25,772 Utility mods for Fabric. 8,071 mods support Minecraft 26.3.

Utility mods36,990Fabric modsMods for 26.38,071

More from ishland

All projects
Concurrent Chunk Management Engine (Fabric)1.17.1 – 26.3Very Many Players (Fabric)1.18 – 26.3ScalableLux1.21 – 26.3Raise Sound Limit Simplified1.17.1 – 26.3Concurrent Chunk Management Engine (NeoForge)1.21.1 – 26.3Fix Keyboard on Linux1.18.2 – 1.21.11

Similar mods

Mod Menu1.14.4 – 26.3Reese's Sodium Options1.16.5 – 26.3Jade 🔍1.16.4 – 26.3Zoomify (Zoom)1.18 – 26.3FancyMenu1.12 – 26.3Indium1.16.5 – 1.21.1

What the author says

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…
ishland, on the Modrinth page

Official listing

Owner
ishland
Published
2023-02-04
Updated on Modrinth
2026-10-05
Facts verified
2026-10-15

Tags

Utility
Open on ModrinthCompare