Ukulib Mod Version Compatibility: 2.x vs Legacy 1.21.x

Ukulib versions encode two pieces of information: the library release itself and the Minecraft version it targets. Reading both parts prevents most accidental cross-version installs.

How the version format works

Ukulib aims to follow semantic versioning and appends a Minecraft target after the plus sign. In 2.2.0+26.3, the 2.2.0 portion is the library version and 26.3 is the intended Minecraft target.

The 2.x line begins with Minecraft 26.1

The official 2.x documentation explicitly covers Minecraft 26.1 and later. Ukulib 2.0.0 also introduced NeoForge support and removed deprecated code, making it a meaningful architectural break from the 1.x line.

Minecraft 1.21.x remains on the 1.x line

The release history includes 1.10.2+1.21.11 for Minecraft 1.21.11, 1.9.0+1.21.9 for 1.21.9–1.21.10, and earlier 1.x builds for older 1.21 releases. Use the build that matches the exact game version and dependent mod requirement.

Loader compatibility is separate from game compatibility

A matching Minecraft number is not enough. Current 2.x setups use loader-specific Fabric or NeoForge builds, so both the Minecraft target and loader must align.

Search phrases can be ambiguous

Queries like “Ukulib Mod 1.21 11” usually mean Minecraft 1.21.11, while “Ukulib 2” refers to the newer major library line. Convert search shorthand into exact release metadata before installing anything.

A safe upgrade rule

Upgrade the library only when the dependent mod accepts the newer version. Keep a backup of the working profile so you can return to the last known-good dependency set quickly.

Continue with the site guides

Use the compatibility section to check versions, then review the troubleshooting section before changing several dependencies at once.