To change your Minecraft server version, go to Startup in the left sidebar, pick the new version from the dropdown, and save. Back up your world in Backups first, worlds can be updated to a newer version but never downgraded to an older one. If you run plugins or mods, check they support the new version before switching, or you'll be greeted with a server that won't boot.
Symptoms
- Server fails to start after switching versions, or the Console shows a crash on boot.
- Plugins silently stop loading, or players get kicked with a version-mismatch message.
- Mods throw missing dependency errors after the jump.
- The world you uploaded or had before won't load on the "new" version you picked.
- Startup errors after switching, usually because a mod or plugin does not support the new version yet.
Why this happens
Minecraft server software (Vanilla, Paper, Fabric, Forge, NeoForge) doesn't always support a given Minecraft version the moment it's released. Paper in particular can lag behind, support staff have repeatedly had to tell customers to hold off upgrading until Paper ships a build for the new version, because plugins simply won't function otherwise. On the modding side, changing versions often breaks mod dependency chains, since mods are built and tested against specific loader and Minecraft version combinations. And regardless of software type, world saves are version-forward only: Mojang's chunk format updates when you load a world on a newer version, and there's no supported way to convert it back down.
How to fix it
- Open Backups and take a fresh backup before touching anything: this is your safety net if the new version breaks your world or setup.
- Go to Startup and check what versions are actually available for your server type (Vanilla, Paper, Fabric, Forge, NeoForge). Not every point release exists for every loader.
- Select the version you want. If you're doing a clean switch and don't need the old world, you can enable the delete-all-files option and accept the EULA when prompted.
- If you're keeping mods or plugins, verify compatibility first: check Plugin Installer or Mods Installer for builds matching your new version before you restart.
- Restart the server and watch Console for errors. Missing dependency or crash messages usually name the exact mod or plugin causing the problem.
- You do not need to set a Java version. Choosing your Server Type selects the correct one automatically.
- If plugins aren't loading and no compatible build exists yet for your new version, revert to your last known-good version in Startup rather than waiting it out mid-session.
Never try to move a world from a newer version back to an older one. It isn't supported and will not load correctly. If you upgraded by mistake, restore from your Backups instead of trying to force a downgrade.
Still stuck?
If the server still won't boot after checking Console and matching your mod and plugin versions, open a support ticket with your server ID and the exact error from Console, staff can confirm whether the version/loader combo you want is actually available and help sort out mod or plugin conflicts.
For mod-specific errors after a version change, see Fix "Missing Dependency" and Mod Conflict Errors and Minecraft Server Won't Start: How to Read the Crash Log. If you're setting up plugins fresh after the switch, check How to Install Plugins on a Spigot or Paper Server. Bringing over a world from elsewhere? See How to Upload Your Own World.
Did this solve it?
If you are still stuck, our team can look at your server directly.