If you see a client update required message, your Rust client is out of date and needs to be updated through Steam before you can join the server.

This usually only happens when Facepunch pushes a forced client update. These updates are commonly released to patch exploits, fix urgent issues, or make sure all players are on the same Rust version.

How to fix it

1. Close Rust completely.
2. Open Steam and check if Rust has an update available. You can do this from your Library or the Downloads page.
3. If an update is available, let Steam finish downloading and installing it.
4. If no update appears, fully exit Steam and reopen it. This often forces Steam to check for the latest Rust update.
5. Check Rust again in your Steam Library.
6. If Rust still does not update, verify the game files. Right-click Rust, click Properties, go to Installed Files, then click Verify integrity of game files.
7. Once Steam finishes, launch Rust and join the server again.