My world or a chunk is corrupted after a mod/version change — how do I recover?

World or chunk corruption after a mod or version change is frustrating, but it's usually recoverable — especially if you kept a backup. The most important first move is to stop loading the corrupt world before it gets worse.

First, stop the server

Stop the server immediately and don't keep loading a corrupt world — each load can deepen the damage. Once it's offline, you can work on recovery calmly.

Recovery options

1. Stop the server immediately.
2. Restore a backup from before the corruption (open your server → Backups), or re-upload a clean copy of the world you saved (via Files/SFTP) — the cleanest fix.
3. If you have no copy, tools like MCA Selector can delete or repair the corrupted chunks (they'll regenerate on next load).
4. If the corruption came from a downgrade, go back to the newer version and restore or re-upload your good copy.

Warning: This is exactly why backups matter — take one before every version/mod change with Back up now on the Backups page (you can also download your own copy via Files/SFTP), and open a ticket if you need help.

Frequently asked questions

What causes chunk corruption? Often a version downgrade, a mod that changed world data being removed, or the server being stopped improperly mid-save. Downgrades are a frequent culprit.

Will deleting corrupt chunks lose my builds? Only the builds in those specific chunks — they regenerate as fresh terrain. MCA Selector lets you target just the damaged chunks.

I have no backup — can you recover it? Check the Backups page first — every server is backed up automatically twice a day. If nothing there helps, open a ticket and staff will see what's possible, but there's no guarantee.