rustdesk/rustdesk · error

Invalid server address: {}

Error message

Invalid server address: {}

What it means

create_online_stream splits the configured rendezvous server address on ':' and requires exactly host:port. If the address has no colon, multiple colons (IPv6 literal), or is empty, this bail fires. The library throws it to fail fast instead of panicking on the tmp[1] index later.

Source

Thrown at src/client.rs:5214

        } else {
            let query_timeout = std::time::Duration::from_millis(3_000);
            match query_online_states_(&ids, query_timeout).await {
                Ok((onlines, offlines)) => {
                    f(onlines, offlines);
                }
                Err(e) => {
                    log::debug!("query onlines, {}", &e);
                }
            }
        }
    }

    async fn create_online_stream() -> ResultType<Stream> {
        let (rendezvous_server, _servers, _contained) =
            crate::get_rendezvous_server(READ_TIMEOUT).await;
        let tmp: Vec<&str> = rendezvous_server.split(":").collect();
        if tmp.len() != 2 {
            bail!("Invalid server address: {}", rendezvous_server);
        }
        let port: u16 = tmp[1].parse()?;
        if port == 0 {
            bail!("Invalid server address: {}", rendezvous_server);
        }
        let online_server = format!("{}:{}", tmp[0], port - 1);
        connect_tcp(online_server, CONNECT_TIMEOUT).await
    }

    async fn query_online_states_(
        ids: &Vec<String>,
        timeout: std::time::Duration,
    ) -> ResultType<(Vec<String>, Vec<String>)> {
        let mut msg_out = RendezvousMessage::new();
        msg_out.set_online_request(OnlineRequest {
            id: Config::get_id(),
            peers: ids.clone(),
            ..Default::default()

View on GitHub (pinned to 91c9fccbb0)

Solutions

1. Set the rendezvous server to a valid 'host:port' pair (e.g. 'rs-ny.example.com:21116') in the client config.
2. If using IPv6, wrap the address in brackets: '[2001:db8::1]:21116'.
3. Check env/config overrides (RENDEZVOUS_SERVERS / custom server settings) for stray characters, spaces, or extra colons.
4. Log rendezvous_server at this point to see the offending value before fixing config.

Example fix

// config before
 rendezvous_server = "rs-ny.example.com"
// after
 rendezvous_server = "rs-ny.example.com:21116"

fn is_valid_rendezvous_addr(addr: &str) -> bool {
    match addr.rsplit_once(':') {
        Some((host, port)) => !host.is_empty() && port.parse::<u16>().map(|p| p > 0).unwrap_or(false),
        None => false,
    }
}

match create_online_stream().await {
    Ok(s) => s,
    Err(e) if e.to_string().contains("Invalid server address") => {
        eprintln!("fix rendezvous server config, got: {}", cfg.rendezvous_server);
        return Err(e);
    }
    Err(e) => return Err(e),
}

When it happens

Trigger: Calling create_online_stream (via query_online_states) when the rendezvous_server string returned by get_rendezvous_server is not of the form 'host:port' — e.g. 'rs-ny.rustdesk.com' without a port, 'host:8000:extra', or an unbracketed IPv6 literal '::1'.

Common situations: Custom rendezvous-server configured without a port in the client config; config value corrupted or truncated; IPv6 server address entered without square brackets; environment override (RENDEZVOUS_SERVERS) with malformed entries.

Understand the failure class

Background: "Invalid URL" errors: why new URL(), URI.parse, and reqwest::Url reject your string — missing scheme, whitespace, and bad path format — this error's family across 39 libraries.

Related errors

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• Incoming only mode
• Failed to secure tcp: {}

AI-assisted analysis of rustdesk/rustdesk@91c9fccbb0 (2026-09-10). Data as JSON: /api/errors/4af7d468c6dc78ae. Report an issue: GitHub.