cloudflare/cloudflared · error

%s

Error message

%s

What it means

When unmarshalling a ConfigurationManager RPC response, the remote side reported an error string (s.Err()). cloudflared wraps that raw string into a Go error verbatim and stores it on the parsed response. The message content is entirely determined by the remote peer.

Source

Thrown at tunnelrpc/pogs/configuration_manager.go:99

	Err                error `json:"err"`
}

func (p *UpdateConfigurationResponse) Marshal(s proto.UpdateConfigurationResponse) error {
	s.SetLatestAppliedVersion(p.LastAppliedVersion)
	if p.Err != nil {
		return s.SetErr(p.Err.Error())
	}
	return nil
}

func (p *UpdateConfigurationResponse) Unmarshal(s proto.UpdateConfigurationResponse) error {
	p.LastAppliedVersion = s.LatestAppliedVersion()
	respErr, err := s.Err()
	if err != nil {
		return err
	}
	if respErr != "" {
		p.Err = fmt.Errorf("%s", respErr)
	}
	return nil
}

View on GitHub (pinned to 2253eeeb25)

Solutions

1. Read the embedded string — it contains the server's explanation.
2. Re-fetch/re-apply configuration; transient remote errors often clear on retry.
3. Verify cloudflared and edge are on compatible versions (update cloudflared).
4. Check tunnel configuration validity in the Cloudflare dashboard.

var resp ConfigurationManagerResponse
if err := resp.Unmarshal(s); err != nil {
    log.Warn().Err(err).Msg("remote configuration apply failed; retrying")
    retryWithBackoff()
}

When it happens

Trigger: Unmarshal of a ConfigurationManager response whose Err field is non-empty; typically surfaces when the server-side configuration apply/reconcile failed.

Common situations: Edge rejects a tunnel configuration update; remote configuration changed concurrently; server hit an internal error while applying configuration; version skew between client and server RPC payloads.

Related errors

• cause
• %s
• %v is not valid IP
• expect to write %d bytes for RPC stream protocol signature,
• expect to write %d bytes for RPC stream protocol signature,

AI-assisted analysis of cloudflare/cloudflared@2253eeeb25 (2026-09-06). Data as JSON: /api/errors/73d1b04bfeff4e08. Report an issue: GitHub.