“I deleted a bunch of chunks, closed MCA Selector, and nothing changed — did it not save?” Or the opposite worry: “where is the save button?” Both questions come from the same misunderstanding, and the answer surprises most people: MCA Selector has no save step at all. Understanding how it actually writes changes explains almost every “changes not saving” report.
How saving actually works in MCA Selector
- Deletions are written the moment you confirm them. Selection → Delete selected chunks and filter-based deletes modify the original region files immediately. The official wiki is blunt about it: “This operation is instant and there is no going back.”
- NBT Changer edits are also instant. When you run a change, it is applied to the files on disk — there is no document to save afterwards.
- The one exception is the Chunk Editor. Editing a single chunk’s NBT tree (Ctrl+B) is staged: nothing is written until you press Apply. Close the editor without Apply and the edit is discarded by design. See our Chunk Editor guide for that workflow.
- Selections are not saved with the world either. If you want to keep a selection itself, export it as a CSV (Selection → Export selection) and import it later — that is the tool’s equivalent of “saving your work area”, as covered in our selection tools guide.
So why did your change “not take”?
- You edited a different folder than you think. The classic case: you opened a backup copy (or a copy you made “just to test”), edited that, then loaded the original in Minecraft. Check the path in File → Open World against the world folder Minecraft actually loads.
- The world was open in Minecraft or on a server while you edited. MCA Selector is an external tool; the game holds its own copy of the world in memory and can overwrite your edits when it saves or shuts down. Always close the world (and stop the server) before editing.
- You closed the Chunk Editor without pressing Apply — see above; that is the one place a “forgot to save” really can happen.
- The change has no visible effect by design. Some NBT Changer fields only matter under specific conditions — ForceBlend, for example, only affects blending between chunks generated by Minecraft 1.18 and its neighbours, so on older terrain it visibly does nothing even though it ran (issues #568/#552 track this confusion upstream).
A safe editing routine
- Close Minecraft completely, and stop your server if the world lives on one.
- Copy the entire world folder somewhere safe — because writes are instant, this copy is your only undo.
- Open that original folder in MCA Selector and double-check the path before changing anything.
- Make your edits. For deletions and NBT Changer, consider them live the second you confirm.
- In the Chunk Editor, press Apply before closing.
- Reopen the world in Minecraft and verify, keeping the backup until you are sure.
Our complete beginner’s guide walks through this routine in context, and the NBT Changer guide covers which fields write what.
If changes genuinely vanish
Work through the four causes above in order — wrong folder and a still-running game or server account for nearly all of them. If the path is right, the game was closed, and an instant operation (a deletion) still leaves the chunk in place when you reload the world in MCA Selector itself, note the exact steps and versions and check the official issue tracker; that combination is unusual enough to be worth reporting.
Get the Current Version First
Several of the problems in this guide disappear on the current release. MCA Selector 2.9 is free and open source — get the Windows installer, the cross-platform .jar, the macOS .dmg or the Linux .deb/.rpm from the MCA Selector download page, where every button points at the official GitHub release files with their SHA-256 checksums.
More troubleshooting
This page is part of our MCA Selector troubleshooting hub, which groups every known launch, loading and editing problem by symptom.