What causes "Error reading configuration: %s" in hyperledger/fabric?

Confirm the file exists and is readable: ls -l and cat the config file directly.

Error reading configuration: %s

Error message

Error reading configuration: %s

What it means

cryptogen's getConfig reads the YAML configuration from the --config file supplied to 'generate'. When io.ReadAll on the opened config file fails, this fmt.Errorf with the OS error is returned. It means the config file could not be read at the OS level, not that the YAML is invalid.

Source

Thrown at cmd/cryptogen/main.go:256

		// "showtemplate" command
	case showtemplate.FullCommand():
		fmt.Print(defaultConfig)
		os.Exit(0)

		// "version" command
	case version.FullCommand():
		printVersion()
	}
}

func getConfig() (*Config, error) {
	var configData string

	if *genConfigFile != nil {
		data, err := io.ReadAll(*genConfigFile)
		if err != nil {
			return nil, fmt.Errorf("Error reading configuration: %s", err)
		}

		configData = string(data)
	} else if *extConfigFile != nil {
		data, err := io.ReadAll(*extConfigFile)
		if err != nil {
			return nil, fmt.Errorf("Error reading configuration: %s", err)
		}

		configData = string(data)
	} else {
		configData = defaultConfig
	}

	config := &Config{}
	err := yaml.Unmarshal([]byte(configData), &config)
	if err != nil {
		return nil, fmt.Errorf("Error Unmarshalling YAML: %s", err)

View on GitHub (pinned to 2736b63f8f)

Solutions

Confirm the file exists and is readable: ls -l and cat the config file directly.
Fix permissions on the config file (chmod/chown) for the user running cryptogen.
Re-copy the config file if it was deleted or truncated.
Run cryptogen without --config to use the default embedded config.

Example fix

// before
cryptogen generate --config /mounts/gone/org.yaml
// after
cryptogen generate --config $(pwd)/crypto-config.yaml

Defensive patterns

Strategy: validation

Validate before calling

cfgPath := "crypto-config.yaml"
info, err := os.Stat(cfgPath)
if err != nil { log.Fatalf("config missing: %v", err) }
if !info.Mode().IsRegular() { log.Fatal("config path is not a regular file") }
f, err := os.OpenFile(cfgPath, os.O_RDONLY, 0)
if err != nil { log.Fatalf("config unreadable: %v", err) }
f.Close()

Prevention

cat the config file before running cryptogen to confirm readability
Use absolute paths for --config
Keep crypto-config.yaml alongside the crypto directory it extends
Omit --config to fall back to the default config when appropriate

When it happens

Trigger: Running 'cryptogen generate --config <file>' where the file exists as a flag but reading it fails: I/O error, deleted between open and read, or a special file that errors on read.

Common situations: Path in a container mount that vanished; file removed by another process between open and read; hardware/IO error on disk; permission denied on read after successful open in restricted environments.

Related errors

AI-assisted analysis of hyperledger/fabric@2736b63f8f (2026-09-04). Data as JSON: /api/errors/2faf61336f8e646b. Report an issue: GitHub.