I am trying to get a new access token using refresh token, but there is always an error: {"error":"invalid_request","error_description":"The request is missing a required parameter, includes an unsupported parameter or parameter value, repeats a parameter, includes multiple credentials, utilizes more than one mechanism for authenticating the client, or is otherwise malformed."} My request is: https://<SERVER>/oxauth/seam/resource/restv1/oxauth/token?grant_type=refresh_token&refresh_token=d0abc921-9615-483f-9485-2c089fc0fc4e&scope=openid Of course, I have the following headers: - Authorization - Content-Type I have also tried to use /oxauth-rp page to validate and everything works fine (I could get access token, id token, refresh token after initial authorization). But I can't receive a new access_token, the choice "refresh_token" is missing from the "grant type" at the token endpoint. [SCREENSHOT](https://1drv.ms/i/s!AlZ45iVqgx6Jg-tokPO1UlyV_gmijA) I am using **Ubuntu 16.04.1 LTS** and apt package for gluu.