You have pruned, reset or repaired your world locally in MCA Selector, and now the edited world has to go back onto the server your players actually connect to. Uploading a world sounds trivial, but most failed uploads share the same few causes: files replaced while the server was still running, only the region folder copied while poi and entities were left behind, or a world uploaded to a server running an older Minecraft version that cannot read it. This guide walks through the whole flow in the safe order.
Before you start
- The local edit is finished and verified. Load the edited copy in single-player once and look at the areas you changed — it is much easier to spot a mistake now than after players log in.
- You have a backup of the edited world on your own machine, separate from the working copy. Our world backup guide covers a workflow that survives bad edits.
- You know which Minecraft version the server runs and that the world matches it (see the DataVersion check below).
- Players know the server will be down. Give the maintenance window a start and an end, not just a surprise disconnect.
Step 1 — Stop the server
Never replace world files on a running server. The server keeps chunks loaded in memory and writes them back as it goes, so files you upload can be silently overwritten — or worse, half-overwritten, which produces corrupt chunks that only show up days later. Use the panel stop button or the stop console command and wait until the process has fully exited before touching any files. The same rule applies to MCA Selector itself: it is an external tool and the world must not be open in the game or on a server while you edit it.
Step 2 — Back up the world that is on the server now
Whatever happens next, the current server world is the version your players last played. Download the complete world folder from the server — through the file manager in your hosting panel or an FTP client — and keep it untouched. If the upload goes wrong, this copy is your way back. Do not skip this because “the new world is better”: player inventories, ender chests and the world itself are all in that folder.
Step 3 — Do the MCA Selector edit locally
Work on a copy of the server world on your own computer. The typical server jobs are pruning chunks outside your world border before a version update, resetting chunks so new terrain generation can appear, or filter-based cleanup of chunks nobody has ever spent time in. Server-specific guidance is in our server world pruning guide. Remember that deletions in MCA Selector are written to the files immediately and cannot be undone — which is exactly why steps 1 and 2 come first.
Step 4 — Upload all three data folders, not just region
A Java Edition world folder holds its terrain data in three sibling folders, and a complete upload needs all three:
region— the block and chunk data itself (the .mca files).poi— points of interest: villagers’ workstations, beds, portals and similar bookkeeping.entities— entities, split out of the region files since Minecraft 1.17.
Uploading only region is the classic mistake: the terrain looks right, but villagers lose their jobs and mobs and items behave as if they were never there. Keep the matching level.dat as well — it carries the world name, seed, spawn point and game rules. If you also edited the Nether or the End, their data lives in DIM-1 and DIM1 subfolders with the same three-folder structure inside.
Step 5 — Panel file manager or FTP?
Both routes work; the right choice is mostly about world size. A hosting panel’s built-in file manager is fine for small worlds and quick fixes, and many panels let you upload a single zip archive and extract it on the server, which is far faster than thousands of small files. For a multi-gigabyte world, an FTP client is the better tool: transfers can resume after a dropped connection and you can queue the three folders and let it run. Whichever route you take, upload to a fresh, empty world folder — do not merge the new files into the old folder, because leftover .mca files from the old world will quietly resurrect chunks you just deleted.
Step 6 — Match the server version to the world’s DataVersion
Every world carries a DataVersion number, and a server can only open worlds its own Minecraft version understands. If the world was last saved by a newer Minecraft version than the server runs, the server will refuse it or damage it — worlds are not backwards-compatible. Check the numbers in our Minecraft DataVersion table before you upload, and if you are moving the world to a newer server version, that upgrade happens once, on first start — another reason the step 2 backup matters.
Step 7 — Start the server and verify in game
- Start the server and watch the console for errors while the world loads.
- Log in and go to the areas you edited: a reset chunk should show freshly generated terrain, a pruned area should end cleanly at your keep boundary.
- Check spawn, a farm or two, and anything entity-heavy (a village is a good test of the
poiandentitiesdata). - Only then announce that the server is back — and keep the pre-upload backup for at least a few days of play.
If something looks wrong
The two usual symptoms are a world that will not load at all (almost always a partial upload or a version mismatch — compare the file counts and sizes against your local copy, and re-check step 6) and a world that loads but “lost” its entities or villager trades (the poi/entities problem from step 4). In both cases the fix is the same: stop the server, restore or re-upload completely, and start again. Do not try to patch a live, half-uploaded world.
No server yet? If you are setting one up so friends can play on the world you just edited, our Minecraft server hosting guide compares the panel hosts and the VPS route, and the server RAM guide helps you size the plan.
Download MCA Selector 2.9
Every server-side job in this guide starts with a local edit. Get the current release from the MCA Selector download page — the Windows installer, the cross-platform .jar, the macOS .dmg and the Linux .deb/.rpm, every button pointing at the official GitHub release files with the SHA-256 checksum listed, plus a clearly labelled site mirror as a fallback. It is free and open source under the MIT licence.