response.StatusCode=500 InternalServerError

[brunozanoelo]

            if (File.Exists(pbixFilePath) == true)
            {
                //DeleteImport(workspace.id, NomedoCubo);

                string restUrlImportPbix = "https://api.powerbi.com/v1.0/myorg/groups/" + workspace + "/imports?datasetDisplayName=" + NomedoCubo + "&nameConflict=CreateOrOverwrite";
                var pbixBodyContent = new StreamContent(File.Open(pbixFilePath, FileMode.Open));

                pbixBodyContent.Headers.Add("Content-Type", "application/octet-stream");
                pbixBodyContent.Headers.Add("Content-Disposition",
                                             @"form-data; name=""file""; filename=""" + pbixFilePath + @"""");


                MultipartFormDataContent requestBody = new MultipartFormDataContent(Guid.NewGuid().ToString());
                requestBody.Add(pbixBodyContent);

                HttpClient client = new HttpClient();
                client.DefaultRequestHeaders.Add("Accept", "application/json");
                client.DefaultRequestHeaders.Add("Authorization", "Bearer " + AccessToken);


                Console.WriteLine("Enviando Cubo: " + NomedoCubo);
                var response = client.PostAsync(restUrlImportPbix, requestBody).Result;

                //  Check de Sucesso
                if (response.StatusCode.ToString().Equals("Accepted"))
                {
                    Console.WriteLine("Processo de Importação efetuado com Sucesso: " + NomedoCubo);
                }
                else {
                    Console.WriteLine("Processo com erro: " + response.StatusCode);
                }
            }
            else {
                Console.WriteLine("Arquivo não encontrado." + NomedoCubo); 
            }

I´m receiving InternalServerError for all my tenant customers. It´s strange because I was using last month andit was workin percfectly. Did anyone found the same problem?

1) I have pro license.
2) It was working properly.

3) My code is the same.