# Installing custom versions of Minecraft

If you want an old mod or modpack to run (Minecraft 1.2.4 and older), this is for you. Warning, not for newcomers!

# Installation:

  1. If you are on Android, install MiXplorer (opens new window) and MiX Archive (opens new window)
  2. Make a copy of the Minecraft version you want to modify
  3. Rename the custom version folder, .jar and .json to your desired custom version name (for example, foo, foo.jar, foo.json)
  4. Open the custom version's .json with MiX's Text Editor
  5. Remove "downloads:{"client"...} as shown in the screenshot


  1. Change "id": "1.2.4" to "id": "(your custom version name)"
  2. Change "mainClass": "net.minecraft.launchwrapper.Launch" to "mainClass": "net.minecraft.client.Minecraft"
  3. Save the .json
  4. Modify your .jar as desired, make sure to delete the META-INF folder afterwards.
  5. Start up your custom version!

# Notes:

  • If your game is stuck at the Mojang screen afterwards, try deleting options.txt
  • This guide is NOT for Babric or Cursed Fabric!