[1.20.1] FML appears to resolve 0.0NONE as a valid version within version constraints

Author: BluSpringCreated Oct 19, 2025Updated Nov 10, 2025
LabelsConfirmedCleanupAssigned1.201.21

Minecraft Version: 1.20.1

Forge Version: 47.4.5, 47.4.10 was also tested afterwards.

Logs: latest.log - https://mclo.gs/IOFGhWY debug.log - https://mclo.gs/8562OTS

Steps to Reproduce:

  1. Install Immersive Vehicles and Immersive Vehicles Official Content Pack
  2. Launch the game
  3. It incorrectly launches (expected: crash due to mismatched version constraint)

Description of issue: When the MANIFEST.MF is missing the Implementation-Version, FML replaces ${file.jarVersion} in the mods.toml with 0.0NONE as expected.

However, when a mod (in this case, mtsofficialpack) requests for a version range of [22.18.0,) and matches it against the replaced 0.0NONE, it erroneously matches correctly.

An additional test was performed with two separate mods built using the MDK:

  • The first mod with the ID weirdforgeversionresolve1, version 1.0.0, which holds a mandatory dependency on weirdforgeversionresolve2 with the version range [22.4.7,).
  • The second mod with the ID weirdforgeversionresolve2, which was built with the Implementation-Version set to 1.0.0 and the mods.toml version manually set to 0.0NONE.

In this test, the game still launched properly despite what should be considered a mismatched version.

Haven't tested yet if this occurs on versions later or earlier than 1.20.1.

Source: MinecraftForge/MinecraftForge