caddyserver/caddy · error

loading fallback encoder module: %v

Error message

loading fallback encoder module: %v

What it means

Error "loading fallback encoder module: %v" thrown in caddyserver/caddy.

Source

Thrown at modules/logging/filterencoder.go:96

// Provision sets up the encoder.
func (fe *FilterEncoder) Provision(ctx caddy.Context) error {
	fe.ctx = ctx

	if fe.WrappedRaw == nil {
		// if wrap is not specified, default to JSON
		fe.wrapped = &JSONEncoder{}
		if p, ok := fe.wrapped.(caddy.Provisioner); ok {
			if err := p.Provision(ctx); err != nil {
				return fmt.Errorf("provisioning fallback encoder module: %v", err)
			}
		}
		fe.wrappedIsDefault = true
	} else {
		// set up wrapped encoder
		val, err := ctx.LoadModule(fe, "WrappedRaw")
		if err != nil {
			return fmt.Errorf("loading fallback encoder module: %v", err)
		}
		fe.wrapped = val.(zapcore.Encoder)
	}

	// set up each field filter
	if fe.Fields == nil {
		fe.Fields = make(map[string]LogFieldFilter)
	}
	vals, err := ctx.LoadModule(fe, "FieldsRaw")
	if err != nil {
		return fmt.Errorf("loading log filter modules: %v", err)
	}
	for fieldName, modIface := range vals.(map[string]any) {
		fe.Fields[fieldName] = modIface.(LogFieldFilter)
	}

	return nil
}

View on GitHub (pinned to 50e54ee279)

Solutions

1. Check the fallback encoder module name and configuration; the wrapped error identifies the problem.

When it happens

Trigger: Thrown at modules/logging/filterencoder.go:96 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of caddyserver/caddy@50e54ee279 (2026-08-15). Data as JSON: /api/errors/85fa8109cb924079. Report an issue: GitHub.