ocols/Authenticator.html#/s:9Alamofire13AuthenticatorP10CredentialQa">Credential</a></code>, or the error that occurred.</p>

<p>In general, if the refresh call fails with certain status codes from the authentication server (commonly a 401),
the refresh token in the <code><a href="../Protocols/Authenticator.html#/s:9Alamofire13AuthenticatorP10CredentialQa">Credential</a></code> can no longer be used to generate a valid <code><a href="../Protocols/Authenticator.html#/s:9Alamofire13AuthenticatorP10CredentialQ