How to Update Minecraft Server Versions Safely (26.3 and the Next Drop)
Back up, check plugins, mods and crossplay, then change the version. Why a world never goes back to an older version, and what to do on the next drop day.
To update Minecraft server software safely, treat it as a one-way trip: take a backup you can restore, check that every plugin, mod and the crossplay bridge has a build for the new version, then switch. A world opened in 26.3 cannot go back to 26.2, so the backup is your only way back.
This guide is for Java Edition and uses our Minecraft Java server panel for the hands-on steps. If you are still setting up, start with our guide to making a free Minecraft server. The latest release today is 26.3; 26.4 is only at snapshot 4, so this post covers 26.3 now and the same routine for the next drop when it lands.
- Backup first. Paper's own update guide calls it "the most important step, and yet the most frequently skipped."
- Plugins and mods lag behind. Paper's first 26.3 build was an alpha on release day; the first stable build came 26 days later.
- Crossplay can switch off. Geyser on our servers runs up to Java 26.2, so a server on 26.3 starts without the Bedrock bridge.
- Never downgrade a world. Restore the backup from before the update instead.
- Players update too. A vanilla server only accepts clients on the same version.
1. Read what the new version changes
Mojang publishes a changelog for every release. The Minecraft Java Edition 26.3 notes (15 September 2026, the Wilderness Bound drop) add the dappled forest biome, poplar trees, abandoned camps, cushions, straw beds and wool and concrete stairs and slabs. For a server admin, the technical section matters more:
| Change in 26.3 | What it means for your server |
|---|---|
| Data Pack version 121.0, Resource Pack version 97.1 | Data packs and server resource packs made for 26.2 may need an update from their author |
white-list is now true by default in server.properties | A brand-new server.properties starts closed. On 1up the panel writes that key from your settings, so your current choice carries over |
| "Some log lines that server software might look out for have been removed" | Tools that read the console log can miss events; Mojang points to its Server Management Protocol instead |
| Explorer Maps become their own items | Old explorer maps in your world "are converted to the matching new item on load", which is part of the one-way upgrade |
| Java 25 | Every 26.x release needs Java 25, according to Mojang's version manifest; 1.21.11 ran on Java 21. Our panel raises the Java version for you when the game version needs it |
Read the changelog of your server software as well. For 26.3, Paper's announcement opens with "backups are absolutely mandatory. After upgrading your world to 26.3, you cannot downgrade back to a lower version!"
2. Take a backup you can restore
A backup is only useful if it holds the whole world folder and you know how to put it back. Paper's updating guide lists three things to save: the world folders, the server configuration files, and the plugin configuration files and plugin jars.
On 1up the Version change assistant takes that backup for you. It is mandatory: the change waits until the backup is stored, and it appears on the Backups tab as "Before the version change". Plans with cloud backups start at Casual (1 backup), Starter keeps 3 and Pro 5; the plans page lists the rest. If every backup slot is taken, the panel stops with "No backup slot is free: unlock or delete one."
On Free there are no cloud backups, so the panel does not let you change the version of an existing server: it is chosen when you create the server. You can still keep your own copy with Export on the Worlds tab or ↓ Download .zip on the Files tab, and that habit is worth keeping on any host.
3. Check plugins, mods and crossplay
Most broken updates come from a plugin or mod built for the old version. Look at three things first.
Your server software. Paper, Fabric and Forge publish builds for each new release on their own schedule. Paper's download API shows the pattern: the first 26.3 build was an alpha on 15 September, and the first build on the stable channel arrived on 11 October. If you run Paper, the safe moment is when the version you want has stable builds.
Your plugins and mods. On the Plugins tab each catalogue entry says "Compatible with 26.3" or "No version for 26.3". The assistant goes further: before you change, it lists every installed plugin with "no compatible build" and warns that they will be disabled. Jars you uploaded by hand through Files are not in that list, so check each one on its download page. Big plugins differ a lot: on Modrinth, LuckPerms marks its regular Bukkit/Paper release as compatible with 26.3, while WorldEdit only had beta builds for 26.3 when we checked. If you run mods, our guide to installing mods on a Minecraft server explains how loader and version must match on both sides.
Bedrock players. Crossplay goes through Geyser, and on our servers it runs on Paper or Fabric up to Java 26.2. Move a crossplay server to 26.3 and it starts without the bridge; the Server tab says so in "Bedrock players". If your Bedrock friends matter more than the new forest, stay on 26.2 for now. Our Java and Bedrock crossplay guide has the details.
4. Change the version in the Worlds tab
With the backup plan clear and the plugin list checked, the change itself takes a minute:
- Tell your players, then stop the server. The assistant only works on a stopped server: "Stop the server to change the version or to revert."
- Open the Worlds tab and find the Version change assistant. It shows the version you play now.
- Pick the new version in the drop-down. Read the lines under it: the automatic backup, the plugins with no compatible build, and how long you can revert.
- Press Change version…. There is no extra confirmation dialog, so check the version once more before you click.
- Wait for the message "Version change under way · the backup is stored first". The panel then shows "You are on 26.3 since the last change, which came from 26.2."
- Start the server and watch the Console. The first start converts the world and takes longer than usual. Join with a 26.3 client and walk around your base before you invite everyone.
The world is kept. The template you chose when creating the server (Vanilla, Paper, Fabric, Forge or Modpack) stays the same. After the change, open Plugins and use Update all to fetch the builds for the new version.
If someone cannot join after the update, the cause is usually a client still on the old version. Our can't connect to a Minecraft server guide covers the version errors and the rest.
5. Why downgrading a world is unsafe
Going back is where most worlds get damaged. The Minecraft Wiki's downgrading tutorial quotes the game's own warning: "Downgrading a world could cause corruption — we cannot guarantee that it will load or work." Blocks and items that do not exist in the older version are removed from the world, and chunks or inventories can be wiped. Paper says it in every release post: after upgrading, "you cannot downgrade back to a lower version."
The safe way back is to restore the backup taken before the update. On 1up the assistant shows ↩ Go back to 26.2 for 7 days after a change. It restores the version and the world from the backup taken before the change, so anything built since the update is lost. After those 7 days, restore the "Before the version change" backup from the Backups tab while it is still kept.
One warning about our own panel: the version drop-down also lists older releases, and today it does not stop you from choosing one for a world that already ran on a newer version. Do not use it to go back. Use ↩ Go back to or a backup.
6. When the next drop lands
Mojang ships 26.4 snapshots every week (snapshot 4 came out on 13 October 2026), and the release date is not announced yet. Snapshots are test builds for single-player experiments; keep them away from a world you care about. When 26.4 comes out, run the same checklist:
- Read the minecraft.net changelog and your server software's announcement. Paper has already said its big config merge is planned for 26.4.
- Wait for stable builds of Paper or your loader, and for your key plugins or mods.
- Check whether Geyser has caught up if Bedrock players join.
- Change the version with the assistant, test, then tell everyone to update their launcher.
Our post on Minecraft version numbers explains what 26.1, 26.3 and 26.4 mean and why the 1.21 series ended at 1.21.11.
Tested on Minecraft: Java Edition 26.3 (our default version) and 26.2, 1up production v0.293.0, 2026-10-13. The panel steps come from our production code and labels, not from a recorded run; plugin and Paper build dates come from Modrinth and the PaperMC download API on the same day.
Change log
- 2026-10-13: first version, for 26.3. Will be refreshed when 26.4 is released.
NOT AN OFFICIAL MINECRAFT SERVICE. NOT APPROVED BY OR ASSOCIATED WITH MOJANG OR MICROSOFT.
Frequently asked questions
NOT AN OFFICIAL MINECRAFT SERVICE. NOT APPROVED BY OR ASSOCIATED WITH MOJANG OR MICROSOFT.