Changing the Minecraft version and server type (Software tab)

You change the Minecraft version and server type in the customer area, in the Software tab. It downloads the software from official sources, verifies it, backs up the server before the change and sets the right Java version on its own. We'll show how to prepare the change, what each option and warning means, and how to go back if something goes wrong.

Before you start#

Backup. The server is backed up automatically before every change, but only if you have a free backup slot. No game server plan includes a backup; you can add a slot as an add-on for 120 CZK a month, see Game server backups. If your only slot is taken by an old backup, delete it in the Backups tab, or download it to your computer first.

Plugins and mods. For every plugin and mod, check that there's a version for the target Minecraft version. Especially with a new version, it often happens that an add-on hasn't been released yet. The server then starts without it, or doesn't start at all.

Downgrade (going back to an older version). Minecraft can only convert a world forwards. Running a world on an older version can corrupt it. Only go back to an older version by restoring a backup, never by switching the version with the same world.

Disk space. The change needs free space for the downloaded software. For Forge and NeoForge it also counts the libraries their installer downloads (about 450 MB). The customer area checks the space itself and won't run the change if there isn't enough.

Changing the version or type step by step#

1. In the customer area, open My services, click the server and go to the Software tab.

2. At the top, under Installed software, note the current state: the type and version (the large heading, for example Paper 1.21.11), Build or Loader, and Java. You'll need them if you want to go back.

3. Under Change software, choose the Server type. You'll find Folia under the Advanced types button. The Minecraft server types article helps you decide which to pick.

4. In the Minecraft version field, choose a version. Latest stable picks the newest released version that has a stable build for the selected type. Test versions appear in the list when you tick Show pre-releases and snapshots. Don't put them on a server with players.

5. In the Build field (Paper, Purpur, Folia) or Loader version (Fabric, Forge, NeoForge), leave Latest stable. Only choose a specific build when a plugin or modpack explicitly requires it.

6. Look at the What will be installed preview. It shows the Server type, Version, Build or Loader, Java and the Download size. Below it, warnings about the specific change appear (we explain them below).

7. If the I understand the risk and want to continue option appears, read the warning and only then tick it. It appears for a downgrade, for an unknown current version and when leaving a modded type.

8. Under Server files, choose the Keep, Clean or Delete all mode (see the table below). For a normal update, choose Keep.

9. Check the backup information. The text “We back up the server before the change.” means everything is fine.

10. Tick I agree to the Minecraft EULA. The customer area then writes your consent to eula.txt. Without it, the server stops after starting unless the EULA was already accepted before (with the Delete all mode, eula.txt is deleted too).

11. Click Change software and confirm. For the Clean and Delete all modes, and for a change without a backup, you confirm with a slider.

    The progress of the change appears below the form.

File modes: Keep, Clean, Delete all#

Clean recognizes the world folder by the level-name setting in server.properties. If you've renamed the world, it's kept under its own name.

Warnings and what to do about them#

How the change runs#

The change runs in five phases: Stop, Backup, Install, Configure and Start.

1. The customer area first downloads the software and verifies its checksum. The server is still running at this point.
2. The server stops.
3. A backup is created with a name starting with pre-switch (for example pre-switch paper 1.21.11 -> paper 26.3 …).
4. Depending on the mode, files are deleted and the new software is installed. Forge and NeoForge are installed by their official installer right on the server. It takes 1 to 5 minutes, you can watch its output in the console, and the server can't be started in the meantime.
5. The startup command, Java version and EULA are set.
6. The server starts again, but only if it was running before the change.

The Show log button shows the detailed progress, and for Forge and NeoForge also the last lines from the installer. If the change fails before any files are touched, the server starts with the old software and nothing changes. If it fails later, the customer area tells you, and you restore the server from the backup taken before the change. If the Forge or NeoForge installer ends with an error, the original startup command and Java version come back too. A message saying the official maven isn't responding means the Forge or NeoForge source is down. Try again in a few minutes.

Java is chosen automatically#

You don't choose the Java version. The customer area picks it based on Mojang's data for the given Minecraft version:

Since 2026, Mojang numbers versions by year and release order (26.1, 26.2, 26.3 …). Version 26.1 came out on March 24, 2026. You can see the current Java version in the Software tab in the Java row.

Reinstalling the same version#

The Reinstall button under Installed software downloads and installs the same version again. The world, plugins, mods and settings stay. It's useful when a server file or library got corrupted and the server won't start, with an error about a missing or damaged .jar file. A reinstall also starts with a backup.

Import: when the customer area doesn't know what the server runs#

For older servers, or when you uploaded the software by hand, a Which software does the server run? form appears instead of the overview.

1. Choose the type and version that the server actually runs. You can find it in the console with the version command, or in the first line of the output on startup.
2. You can leave the Build (optional) field empty. For Forge and NeoForge, the customer area finds the loader version itself in the startup command or in the server files (the libraries folder). Only fill it in if it says it couldn't find the file the server starts from.
3. Click Save state.

An import doesn't change any files; it only tells the customer area what's on the server. After that, Reinstall, the downgrade check and the Startup tab work.

Recommended way to update to a new version#

1. Check that all your plugins or mods have a version for the target Minecraft version.
2. Let your players know about the downtime.
3. Free up a backup slot.
4. In the Software tab, choose the same type, the new version and the Keep mode.
5. When it's done, check the console. Look for ERROR lines and plugins or mods that didn't load.
6. In the Plugins (or Mods) tab, click Check for updates and update your add-ons.
7. Restart the server and join. Walk around spawn and your builds.

Going back#

If the new version doesn't work, restore the pre-switch backup and then switch the software back too.

1. Go to the Backups tab.
2. Find the backup whose name starts with pre-switch from the time of the change.
3. Click Restore.
4. Tick Delete all current files before restoring. Otherwise files that aren't in the backup stay on the server, for example new plugin versions.
5. Confirm the restore and wait for it to finish.
6. Open the Software tab. The backup only restores files. The customer area sets the startup command and Java version based on the most recently installed software. If Installed software still shows the new version, under Change software click the same type, choose the old version (the one you noted down) and the Keep mode.
7. Confirm the downgrade warning with I understand the risk and want to continue. The world in the restored backup is in the old version, so nothing gets converted.
8. The backup slot is now most likely taken by the pre-switch backup, so “All backup slots are used” appears. As the owner, tick Continue without a backup. The files on the server are now the same as in the pre-switch backup, which stays saved. A member of a shared service doesn't have this option; the owner has to do this step.
9. Click Change software and confirm.

Verify it works#

• In the Software tab, Installed software shows the new version and type.
• In the console, the version command prints the same version.
• On startup, the server gets all the way to the Done (…)! For help, type "help" line.

Troubleshooting#

“All backup slots are used”#

Delete an old backup (or download it and then delete it) in the Backups tab and run the change again. The service owner can tick Continue without a backup, but then the change can't be undone.

“Backups are not enabled for this server”#

The server has no backup slot. Buy one, or, as the owner, continue with the Continue without a backup option. A member of a shared service can't continue without a backup.

“Version … has no stable build yet”#

There's no stable release for the selected type yet. This typically happens in the first few days after a new Minecraft version comes out. Wait, or choose the previous version.

“This version is already running”#

You selected the same type, version and build. To repair a damaged installation, use Reinstall.

“There is not enough free disk space”#

Free up space in the Files tab (old world backups, logs in the logs folder, unused worlds), or upgrade your plan in the Change plan tab.

“We support Forge from version 1.17.”#

Older Forge versions can't be deployed from the installer. Choose a newer Minecraft version, or contact support.

The server won't start after the change#

Open the Console tab and find the first ERROR line. Most often it's a plugin or mod that doesn't support the new version. Disable it in the Plugins (Mods) tab and start the server again. Other messages are explained in Common Minecraft server errors.

“Nothing can be changed on the server right now”#

Another operation is running on the server, for example a backup restore or an installation. Wait for it to finish and try again.

Further reading#

• Paper 26.1: changes for server admins (opens in a new window)
• Minecraft Wiki: Java Edition version history (opens in a new window)