A plugin does not support this server version

[15:30:04 INFO]: [Essentials] Enabling Essentials v2.20.1
[15:30:04 ERROR]: [Essentials] You are running an unsupported server version!
[15:30:05 INFO]: [Essentials] Using LuckPerms based permissions with Vault.

What it means

Some plugins check the server’s Minecraft version and software when they start and compare it with the versions they were built and tested for. The diagnosis reads the wording EssentialsX prints when the server is not one of them: You are running an unsupported server version!.

The plugin does not stop. It goes on enabled, but code that depends on the server’s internals may fail later, often as errors while players use its commands or when events fire. It is reported as an error because those failures are likely, not certain.

Why it happens

• The server is newer than the plugin. The server was updated to a Minecraft version that came out after the plugin’s build. This is the most common case.
• The server is older than the plugin supports. Current builds drop support for old Minecraft versions.
• The server software is not one the plugin was tested on. A fork, or a server that mixes plugins and mods, can report a version the plugin does not recognise.

How to fix

1. Check the plugin’s page for a build that supports your Minecraft version and server software. For EssentialsX, a development build may support a new Minecraft version before the next release does.
2. Replace the jar in the plugins folder with that build and restart the server.
3. If no build supports your version yet, either keep the server on a Minecraft version the plugin supports, or accept that parts of it may fail. Moving the server back to an older Minecraft version can damage the world, so take a backup and do not downgrade a world without one.
4. Watch the Diagnosis tab after the restart for errors from the same plugin.

In Perland

The issue appears in the server’s Diagnosis tab with the plugin that printed it. Plugin Studio can update the plugin to a newer build or replace it with an uploaded jar, and the server’s version is set in Settings.

References

• EssentialsX