404. That’s an error.
The requested URL /users/oauth/?server=facebook&nv_redirect=RpdZSbwN1_k4SdvO1XQl0YySFeCKLeMLIjOIwgLNUpCClYvKEbRiVkjwRYbSkPGFXxmyyqmDlQHpAFzWzUsv0gVcELV3lJYqbRyjVxinVvUPviPcGdT9HEUvaMYbss_n
was not found on this server. That’s all we know.