Fix the NullReferenceException Connection Error on a New Rust Server

Published 9 June 2026 · By Host Havoc Technical Support Team

A newly created Rust server will disconnect you with the following error if it has not been configured yet:

Disconnected: Exception (cs: 73433): NullReferenceException: Object reference not set to an instance of an object.
AdaptMeshToTerrain.Adapt()

This happens because no map has been selected. The server cannot generate a world without a seed and map size. Follow the steps below to resolve it. See Change Hostname to set other basic server settings at the same time.

Steps

  1. Navigate to your server in the Game Control Panel.
  2. Stop the server.
  3. Click Configuration Files and open server.cfg using the Config Editor.
  4. Make your desired configuration changes. Scroll to the bottom of the config and set your level/map settings, including the seed and size values.
  5. Click Save and Exit.
  6. Start the server.

The server will now generate a world using the seed and size you specified, and you will be able to connect.