This page has been created to explain how to migrate the mod “Castle defenders 1.2 for Minecraft 1.5.2” to the version “3.0.0 for Minecraft 1.6.4”. Then easily to Minecraft 1.7.2 or 1.7.10.

The main problem is if you don’t migrate first to 3.0.0 – 1.6.4 your Castle defenders blocks will disappear. You need to load your world with the 1.6.4 version first, then step to the next version.

The migration remains simple and only consists on putting the right block IDs and activating the compatibility into the Castle Defenders config file then loading your worlds with Castle Defenders 3.0.0 on Minecraft 1.6.4 before any migration to 1.7.*. But this tutorial will explain you the whole procedure, in order to prevent any issue.


  • Castle Defenders 1.2 available here
  • Castle Defenders 3.0.0 – 1.6.4 available here
  • Gollum Core Lib 2.0.0 available here
  • Minecraft 1.5.2 with forge
  • Minecraft 1.6.4 with forge

Load Castle Defenders 1.2

  • Start Minecraft with Castle Defenders 1.2 loaded.
  • Create a Test world in creative mode and place all the Castle Defenders 1.2 blocks (there are only 8, it mustn’t be hard).
  • Save then Exit Minecraft.
Minecraft folder on windows


Migrating the config file

In order to prevent any block loss, you have to match the 1.2 IDs with the 3.0.0 IDs, using the config file.

  • Search for config/CastleDef.cfg in Minecraft subfolder and open it.
  • Go to the config file migration page.
  • Download the CastleDefenders.cfg file and put it in the Minecraft subfolder config/.
  • Make sure the file contains that option: compatibilityWithOldVersion=true. If not, you may have done something wrong during the procedure.

Testing in the world

  • Re-launch Minecraft, but this time using CastleDefenders 3.0.0 and Minecraft 1.6.4 (don’t forget to remove Castle Defenders 1.2).
  • Load the Test world you created.
  • You should be warned about Missmatched blocks, simply answer “Yes”. You must only have Missmatched blocks, and not Missing blocks.
  • Check your blocks and make sure they are all there.
Message migration success

mismatched Block castle

Message migration fail

missing Block castle

Migrating your worlds

  • Go to the Minecraft subforlder saves/.
  • Make a backup of all your worlds and other mod or config folders on your desktop (copy/paste on your desktop).
  • Re-launch Minecraft 1.6.4 with the right configuration and Castle Defenders 3.0.0.
  • Launch your world and agree the migration.
  • All your blocks should be there.

Migrating to 1.7.*

If you already migrated to 3.0.0-1.6.4, there is no special task or configuration needed to migrate to 1.7.*. You only have to change Minecraft and the mod versions.