AdguardTeam/AdGuardHome · error

generating config file: %w

Error message

generating config file: %w

What it means

Writing the config file object failed at the YAML encoding stage: yaml.Encoder could not serialize the configuration into bytes. Encoding errors usually reflect unmarshalable or incompatible field types after schema changes.

Source

Thrown at internal/home/config.go:917

		dns.UpstreamTimeout = timeutil.Duration(s.UpstreamTimeout())
	}

	if globalContext.dhcpServer != nil {
		globalContext.dhcpServer.WriteDiskConfig(config.DHCP)
	}

	config.Clients.Persistent = globalContext.clients.forConfig()

	confPath = configFilePath(ctx, l, workDir, confPath)
	l.DebugContext(ctx, "writing config file", "path", confPath)

	buf := &bytes.Buffer{}
	enc := yaml.NewEncoder(buf)
	enc.SetIndent(2)

	err = enc.Encode(config)
	if err != nil {
		return fmt.Errorf("generating config file: %w", err)
	}

	err = maybe.WriteFile(confPath, buf.Bytes(), aghos.DefaultPermFile)
	if err != nil {
		return fmt.Errorf("writing config file: %w", err)
	}

	return nil
}

// validateTLSCipherIDs validates the custom TLS cipher suite IDs.
func validateTLSCipherIDs(cipherIDs []string) (err error) {
	if len(cipherIDs) == 0 {
		return nil
	}

	_, err = aghtls.ParseCiphers(cipherIDs)
	if err != nil {

View on GitHub (pinned to b41aefbe51)

Solutions

1. Check the wrapped error for the offending field
2. Recreate the config from a known-good backup instead of the corrupted state
3. Upgrade to a consistent AdGuard Home version (avoid mixing binaries and data from different releases)

// Fall back to last known-good config file
if err := persistConfig(cfg); err != nil { cfg = loadBackup() }

When it happens

Trigger: Persisting config (e.g. after a setup/PUT /control/config or internal update) where some field of the config struct cannot be marshaled to YAML.

Common situations: Version mismatches or corrupted in-memory config after partial upgrades; exotic custom types injected by plugins; extremely rare in stock builds.

Related errors

• generating new config: %w
• writing conf: %w
• parsing config file for upgrade: %w
• unexpected type of upstream field: %T
• persistent client at index %d: unexpected type %T

AI-assisted analysis of AdguardTeam/AdGuardHome@b41aefbe51 (2026-08-27). Data as JSON: /api/errors/2ac83c8c51f1b36e. Report an issue: GitHub.