update-1.0.0-neoforge-26.1.2.jar is an alpha file of the Minecraft mod old_world.jar for NeoForge, made for Minecraft 26.1.2. It was published on October 6, 2026 and is 0.6 MB in size. Pre-release builds can contain bugs — back up your world before installing. For the full description, screenshots and every other version, visit the old_world.jar mod page.
How to install: Put the .jar into the mods folder (.minecraft/mods) and start Minecraft with the matching mod loader profile.
