criticalServer ErrorsAffects: All versions
How to Fix World Corruption
Fix world corruption by restoring from backup, using level.dat_old, or deleting corrupted region files.
Quick Fix
Restore from a backup. If no backup, try restoring level.dat_old by renaming it to level.dat.
Error Message
Exception generating new chunk / Failed to load level.datHow to Fix
1
Restore the world from the most recent backup
2
If level.dat is corrupted, rename level.dat_old to level.dat
3
Use NBTExplorer to inspect and repair NBT data
4
Delete corrupted region files (r.X.Z.mca) to regenerate those chunks
5
Run the world through the Minecraft built-in optimizer (on singleplayer)
Common Causes
- Server or game crashed during world save
- Disk ran out of space during save
- Force-closing Minecraft while saving
- Power outage during gameplay
- Corrupted level.dat or region files
Diagnostic Steps
- Make a backup of the current corrupted world (just in case)
- Try renaming level.dat_old to level.dat
- If that does not work, identify corrupted region files
- Delete corrupted .mca files and let them regenerate
- Load the world
FAQ
How do I prevent world corruption?
Never force-close Minecraft, use auto-save plugins, keep regular backups, and ensure adequate disk space.
Can I recover a corrupted world without a backup?
Sometimes. Try level.dat_old first. You can also delete corrupted region files, but those chunks will be regenerated as new terrain.