Operation returned an invalid status code 'Forbidden' GenerateTokenInGroupAsync

Hi All,

I am getting an error while executing the GenerateTokenInGroupAsync().  The error "Operation returned an invalid status code 'Forbidden'".  

I had users using the system all day, and the late afternoon this just stopped working.  I am using the following method to get the access token.

public static async Task<AccessToken> SetAccessToken()
        {
            List<KeyValuePair<string, string>> vals = new List<KeyValuePair<string, string>>
            {
                new KeyValuePair<string, string>("grant_type", "password"),
                new KeyValuePair<string, string>("scope", "openid"),
                new KeyValuePair<string, string>("resource", "https://analysis.windows.net/powerbi/api"),
                new KeyValuePair<string, string>("client_id", "XXXXX"),
                new KeyValuePair<string, string>("client_secret", "XXXXX"),
                new KeyValuePair<string, string>("username", "XXX"),
                new KeyValuePair<string, string>("password", "XXX")
            };
            string TenantId = "XXX";
            string url = string.Format("https://login.windows.net/{0}/oauth2/token", TenantId);
            HttpClient hc = new HttpClient();
            HttpContent content = new FormUrlEncodedContent(vals);
            HttpResponseMessage hrm = hc.PostAsync(url, content).Result;
            string responseData = "";
            if (hrm.IsSuccessStatusCode)
            {
                Stream data = await hrm.Content.ReadAsStreamAsync();
                using (StreamReader reader = new StreamReader(data, Encoding.UTF8))
                {
                    responseData = reader.ReadToEnd();
                }
            }
            AccessToken token = JsonConvert.DeserializeObject<AccessToken>(responseData);

            return token;
        }

I can retrieve the report details using client.Reports.GetReportInGroupAsync().

var report = await client.Reports.GetReportInGroupAsync(groupId, reportId, CancellationToken.None);
var generateTokenRequestParamaters = new GenerateTokenRequest(TokenAccessLevel.View, datasetId, allowSaveAs: null);
var tokenResponse = await client.Reports.GenerateTokenInGroupAsync(groupId, report.Id, generateTokenRequestParamaters, CancellationToken.None);

The error occurs when executing the last line of code in the code above.

Regards

Remeez