ory/kratos · error

received unexpected message template type

Error message

received unexpected message template type: %s

What it means

NewEmailTemplateFromMessage switched over the message's template type and fell through every known case into the default branch. The stored TemplateType string does not match any email template the running courier binary knows about, typically because the message was written by a newer/older kratos version than the courier processing it.

Solutions

1. Upgrade the kratos and courier components to matching versions so template types align
2. Inspect the queued message's template_type value to identify the mismatch
3. Drain or delete stale queued messages produced by the incompatible version

When it happens

Trigger: Thrown at courier/email_templates.go:118 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of ory/kratos@b86338da04 (2026-09-07). Data as JSON: /api/errors/aab127eb3891dbec. Report an issue: GitHub.

Appendix: source

Thrown at courier/email_templates.go:118

		var t email.RegistrationCodeValidModel
		if err := json.Unmarshal(msg.TemplateData, &t); err != nil {
			return nil, err
		}
		return email.NewRegistrationCodeValid(d, &t), nil
	case template.TypeVerifiableAddressChanged:
		var t email.VerifiableAddressChangedModel
		if err := json.Unmarshal(msg.TemplateData, &t); err != nil {
			return nil, err
		}
		return email.NewVerifiableAddressChanged(d, &t), nil
	case template.TypeAuthenticatorKeyAdded:
		var t email.AuthenticatorKeyAddedModel
		if err := json.Unmarshal(msg.TemplateData, &t); err != nil {
			return nil, err
		}
		return email.NewAuthenticatorKeyAdded(d, &t), nil
	default:
		return nil, errors.Errorf("received unexpected message template type: %s", msg.TemplateType)
	}
}

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