Fixing Lavalink Closed Abnormally Errors on Virtus Cloud

If your music bot uses Lavalink for audio playback and you’re seeing WebSocket errors when it tries to connect to your Lavalink server, the root cause is almost always a version mismatch between your Lavalink server and the Lavalink client library your bot uses. Starting with Lavalink v4, the server switched from a WebSocket-first protocol to a fully REST-based API — older client libraries that expect a direct WebSocket connection will fail immediately with a 400 response and a 1006 close code. This guide walks you through the correct fix and includes the essential port configuration steps required to make Lavalink work on Virtus Cloud.

When Does It Occur?

You’ll see one or both of the following errors in your application logs when your bot attempts to connect to a Lavalink server:

Error: Unexpected server response: 400
Error: WebSocket closed abnormally with code 1006.

The errors appear at startup or whenever your bot tries to establish the audio session, and the connection never completes successfully.

Why Does It Occur?

Lavalink v4 (and later) uses a fully REST-based architecture. The client no longer initiates a direct WebSocket upgrade from the bot’s side in the same way as earlier versions. If your Lavalink client library was written for Lavalink v3 or earlier, it tries to open a WebSocket connection that the v4 server doesn’t accept — resulting in a 400 Bad Request response, which causes the WebSocket handshake to fail with close code 1006. In short: your Lavalink server version and your Lavalink client library version must be compatible with each other.

How to Fix It

You have two options: update your client library to one that supports your server version, or downgrade your server to match your existing client.

Option 1 — Update the Lavalink client library (recommended)
Option 2 — Use a Lavalink server version compatible with your client

Updating the client library is the preferred approach because it keeps your server on the latest stable release.

Identify your Lavalink client library

Common Lavalink client libraries for Discord bots include lavalink-client, erela.js, shoukaku, poru, and lavaclient. Check your package.json or requirements.txt to find which one you’re using.

Find a v4-compatible version

Look up your library on npm or PyPI and identify the version that adds Lavalink v4 support. Most popular libraries released a major version bump when they added v4 compatibility — check the library’s changelog or README for guidance.

Update your dependency file

Update the version in your package.json or requirements.txt:

{
  "dependencies": {
    "lavalink-client": "^2.3.2"
  }
}

Update your connection code

Lavalink v4-compatible clients often have slightly different connection option signatures. Consult your library’s migration guide for any breaking changes. A typical Lavalink v4 connection configuration looks like:

const client = new LavalinkClient({
  nodes: [
    {
      host: 'your-lavalink-host.virtusapp.cloud',
      port: 443,
      authorization: 'your-password',
      secure: true,
    }
  ]
});

Redeploy your application

Save your changes and redeploy from the Virtus Cloud dashboard. Watch the startup logs to confirm the Lavalink connection succeeds.

Required Port Configuration for Virtus Cloud

Regardless of which Lavalink version you use, you must follow these Virtus Cloud-specific port rules for Lavalink to work correctly:

Lavalink server must listen on port 80

When hosting your Lavalink server as an application on Virtus Cloud, configure it to listen on port 80 (the platform’s default HTTP port). Set this in your Lavalink application.yml:

application.yml

server:
  port: 80
  address: 0.0.0.0

Your bot must connect using port 443 with secure: true

Virtus Cloud terminates TLS at the edge and forwards traffic internally over HTTP. Your bot must connect to the Lavalink server using port 443 (HTTPS/WSS) with the secure: true option. The platform handles the SSL handshake, so your Lavalink server doesn’t need an SSL certificate.

nodes: [
  {
    host: 'your-lavalink-subdomain.virtusapp.cloud',
    port: 443,
    authorization: 'your-password',
    secure: true,
  }
]

After resolving the version mismatch and configuring the correct ports, restart both your Lavalink server and your bot. The connection should complete successfully and your music commands should work as expected.

If you continue to experience Lavalink connection errors after following these steps, contact the Virtus Cloud support team.

​When Does It Occur?

​Why Does It Occur?

​How to Fix It

​Required Port Configuration for Virtus Cloud

When Does It Occur?

Why Does It Occur?

How to Fix It

Required Port Configuration for Virtus Cloud