This page guides you through setting up a backup mod and/or recovering a corrupt world.

Backup Options

Depending on your skill level and PC ability, there are a couple of backup options.

Copy everything

This, of course, has to be done manually. You can write a simple batch file script to do it as well. Make sure you capture everything in your save directory, as well as journeymap and tcnodefinder directories. Best to do this before or after each gaming session.

Pros

Can write script to copy exactly what you want.
Make it fancy by zipping up the directories, or only doing differences from the last backup.

Cons

Requires expertise in PC
Generally, can only do backup while not playing.
Have to restore files from command line.

Aromabackup

[Aromabackup] is a common mod used to backup games. It is configurable for how often to backup and how many backups to keep around. It will require a [core mod] as well.

Pros

Config file for where to store backups, how often to take them, and how many to save
Easy to use in-game interface to restore from backup.

Cons

Options might be a little flaky - keep an eye on HD usage, and flush old backups occasionally.
Does not backup Journeymap or tcnodefinder directories.

FTB Utilities

Recovery Options

Once you've made your backups, a time will come when you have to restore them, whether your world corrupts itself, your quests glitch up, or you just blow up all your machines in a freak transformer accident.

From a .zip file

Restoring from a .zip file is quite easy. Simply open up the .zip file, and copy-and-paste the world's folder from the .zip into your saves folder.

Aromabackup

Aromabackups stores its backups in a location of your choice, by default they are stored in the "backups" folder in the GTNH folder. Simply go there, click on the year, month, and day of backup, select the right backup based on the timestamp, then follow the .zip restoration guide to restore it.

FTB Utilities

ZOMG! I am an idiot and did not backup my game!

Well, sad times. There are some options you can try here, but they all will require expertise in Minecraft files.

Try looking at the crash log in logs/latest.log and see what may be causing the issue.

Corrupt chunk

If the crash file identifies the corrupt chunk or Region file (each Region file is 32x32 chunks), then you can try these steps

First, backup your level.dat and level.dat_old files.
Delete level.dat and rename level.dat_old -> level.dat
If this works, great! If not, continue...
Copy the whole save folder to create backup. Also save off your Journeymap and tcnodefinder directories now too.
Go through the .mca files in the save dir and delete them one by one to find out which region file is corrupted. If you have an idea which chunk might be causing it, you can look at the pictures in the Journeymap directory to see which region file it may be. The names of the pictures in the Journeymap directory correspond to the region.
Once you know the corrupt .mca file, you can decide to delete or repair it. If the Journeymap for that chunk shows nothing important, it's ok to delete. Minecraft will regenerate the chunks fresh next time you login.
If you need to repair (chunk with base or whatever) use a map editor / NBT editor to import the mca file and edit just the bad block or entities.
Advanced Users Only: You can use this tool, provided by bartimaeusnek, which will split up an MCA File to Chunks: https://github.com/bartimaeusnek/RegionSplitter/releases/download/0.0.2/RegionSplitter0.0.2.jar