Plugin Data Migration Guide

Minecraft 26.1 introduced a new world directory format.
If a plugin stores world-related data inside the directory of each corresponding world, upgrading from Minecraft 1.21.11 or older to 26.1 or newer may require a manual migration.

This can affect plugin data such as portals, holograms, areas, or other files that were stored directly in an old world folder.

Before upgrading your server: MAKE BACKUPS!!!
This is always important, but especially this time!

Migration steps

1. BACK UP YOUR SERVER. This is a hard requirement or you may lose almost everything.
2. Update your server jar to the latest build. At the time of writing, that is 26.1.2.
3. Start your server and wait 30 seconds. You will see a big warning about making backups.
4. Stop your server again.
5. Open the world folder of your updated server in one file explorer window, and the world folder from your backup in another.
6. The world folder of your updated server might still contain old plugin data folders you can remove, for example portals, holograms, areas, or similar plugin-specific folders.
7. Check the new and old world folder names below, then open the matching folders in both file explorer windows.
8. Copy the plugin data folder or folders from the backup world into the updated world's data folder.
9. Repeat steps 7 and 8 until you have covered all of your worlds.
10. Start your updated server and verify that the data is recognized correctly and nothing is missing.

You can also follow the video for a visual walkthrough of the process.

New vs old world folder names

These are only the default folder names. If you previously configured a different world name in your server.properties, your old folder name will be different.

If you have trouble with the migration process, feel free to ask for help in our Discord.

P.S. MAKE BACKUPS!!! As many as you can. The more, the better.