Bad Request Error when create Team meeting with Application token

Question

I'm trying to use Application token to create a meeting on behalf of a user and is getting error Bad Request - Request payload cannot be null. I'm able to generate access token, get User object.

Do I need to Configure application access policy (I have no idea where to find this on Azure portal)? Your help is greatly appreciated.

Json payload

"{\"subject\":\"Test Online Meeting for Team 2025 a\",\"startDateTime\":\"2025-03-01T10:00:00Z\",\"endDateTime\":\"2025-03-01T11:00:00Z\",\"accessLevel\":\"everyone\",\"entryExitAnnouncement\":true,\"body\":{\"content\":\"\"},\"participants\":{\"organizier\":{\"identity\":{\"user\":{\"id\":\"aa005b40-9bcb-465d-ac17-56b50ee99e3e\"}}}}}"

Create meeting code

try
{
  string user_id = "aa005b40-9bcb-465d-ac17-56b50ee99e3e";
  using (HttpClient httpClient = new HttpClient())
  {
    httpClient.BaseAddress = new Uri("https://graph.microsoft.com/v1.0/me/onlineMeetings");
    httpClient.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
    httpClient.DefaultRequestHeaders.Add("authorization", "Bearer " + accessToken + "");

    var content = new StringContent(jsonobj.ToString(), System.Text.Encoding.UTF8, "application/json");

    servicerequest = httpClient.PostAsync("https://graph.microsoft.com/v1.0/{user_id}/onlineMeetings", content).Result;
    string response = servicerequest.Content.ReadAsStringAsync().Result;
    meetingObj = JsonConvert.DeserializeObject<TeamsMeetingEventObj>(response);

    String OnlineTeamLink = meetingObj.join_WebUrl.ToString();

  }
}
catch (Exception ex)
{
  meetingObj.general_message = "Exception: " + ex.Message;
}

This is the API Permission

Decode of Access Token

{
  "typ": "JWT",
  "nonce": "O0k-Dr8iF7CHKVRRoieNaaWlzrR1H3Q7MkJ6_zDjsYw",
  "alg": "RS256",
  "x5t": "imi0Y2z0dYKxBttAqK_Tt5hYBTk",
  "kid": "imi0Y2z0dYKxBttAqK_Tt5hYBTk"
}.{
  "aud": "https://graph.microsoft.com",
  "iss": "https://sts.windows.net/d411855d-e0b2-480b-93d7-cba60cxxxxxx",
  "iat": 1739862965,
  "nbf": 1739862965,
  "exp": 1739866865,
  "aio": "k2RgYCj+P1Fzzf+uAvP7rUvv/Nxxxxxx",
  "app_displayname": "Teams Integration",
  "appid": "2faa523d-93e5-4f0e-b129-247ae7xxxxxx",
  "appidacr": "1",
  "idp": "https://sts.windows.net/d411855d-e0b2-480b-93d7-cba60cxxxxxx/",
  "idtyp": "app",
  "oid": "11dc9a92-88a3-46c3-82c6-58369axxxxxx",
  "rh": "1.AWEBXYUR1LLgC0iT18umDPso7gMAAAAAAAAAwAAAAAAAAABiAQBhAQ.",
  "roles": [
    "OnlineMeetings.ReadWrite.All",
    "Application.ReadWrite.OwnedBy",
    "Calendars.ReadWrite",
    "Application.Read.All",
    "Reports.Read.All"
  ],
  "sub": "11dc9a92-88a3-46c3-82c6-58369axxxxxx",
  "tenant_region_scope": "NA",
  "tid": "d411855d-e0b2-480b-93d7-cba60cxxxxxx",
  "uti": "yz1WwGN5XEqtGSUbtvXZAA",
  "ver": "1.0",
  "wids": [
    "0997a1d0-0d1d-4acb-b408-d5ca73xxxxxx"
  ],
  "xms_idrel": "6 7",
  "xms_tcdt": 1738391941
}.[Signature]

This is the error

{BadRequest} - {\"error\":{\"code\":\"General\",\"message\":\"Request payload cannot be null.\",\"innerError\":{\"request-id\":\"d2bd44f7-46c2-47b3-8239-a159264b0a0f\",\"date\":\"2025-02-19T09:09:26\",\"client-request-id\":\"d2bd44f7-46c2-47b3-8239-a159264b0a0f\"}}}"


{StatusCode: 400, ReasonPhrase: 'Bad Request', Version: 1.1, Content: System.Net.Http.StreamContent, Headers:
{
  Transfer-Encoding: chunked
  Strict-Transport-Security: max-age=31536000
  request-id: f3af64c0-dddf-4055-962f-53a9a821b990
  client-request-id: f3af64c0-dddf-4055-962f-53a9a821b990
  x-ms-ags-diagnostic: {"ServerInfo":{"DataCenter":"West US 3","Slice":"E","Ring":"2","ScaleUnit":"000","RoleInstance":"PH1PEPF00011630"}}
  scenario-id: 67df8b07-7824-4a72-8c02-68a59e482571
  Date: Wed, 19 Feb 2025 16:25:25 GMT
  Content-Type: application/json
}}

Answer 1

I got the same error message, When I tried the code provided by you:

Initially, Registered Single Tenant Microsoft Entra ID Application, Added Application type OnlineMeetings.ReadWrite.All API Permission and Granted Admin Consent like below:

Note: For using Application type API permission needs to use client-credentials flow only.

Ensure to create and configure application access policy for your application.Refer this MsDoc,

Use below Powershell Script for creating and configuring application access Policy:

Install-Module -Name MicrosoftTeams -Force -AllowClobber #If not installed
Import-Module MicrosoftTeams

Connect-MicrosoftTeams

New-CsApplicationAccessPolicy -Identity Demo-policy -AppIds "<app-id>" -Description "Allow access to Teams App"

Grant-CsApplicationAccessPolicy -PolicyName Demo-policy -Global

Use below modified C# script:

using System;
using System.Net.Http;
using System.Text;
using System.Text.Json;
using System.Threading.Tasks;
using Azure.Identity;
using Microsoft.Graph;

class Program
{
    private static readonly string tenantId = "<tenant-id>";
    private static readonly string clientId = "<client-id>";
    private static readonly string clientSecret = "<client-secret>";
    private static readonly string organizerUserId = "<user-id>"; // Organizer's Azure ID

    static async Task Main()
    {
        try
        {
            var graphClient = GetGraphClient();
            string meetingLink = await CreateTeamsMeeting(graphClient);

            if (!string.IsNullOrEmpty(meetingLink))
            {
                Console.WriteLine("Meeting Created Successfully!");
                Console.WriteLine("Join URL: " + meetingLink);
            }
            else
            {
                Console.WriteLine("Failed to create meeting.");
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine($"Exception: {ex.Message}");
        }
    }

    /// <summary>
    /// Authenticates and returns a GraphServiceClient using client credentials flow.
    /// </summary>
    private static GraphServiceClient GetGraphClient()
    {
        var options = new ClientSecretCredential(tenantId, clientId, clientSecret);
        return new GraphServiceClient(options);
    }

    /// <summary>
    /// Creates a Microsoft Teams online meeting with Access Level "everyone".
    /// </summary>
    private static async Task<string> CreateTeamsMeeting(GraphServiceClient graphClient)
    {
        var httpClient = new HttpClient();
        string token = await GetAccessToken();

        var requestBody = new
        {
            subject = "Test Online Meeting for Team 2025 a",
            startDateTime = "2025-03-01T10:00:00Z",
            endDateTime = "2025-03-01T11:00:00Z",
            accessLevel = "everyone",  
            participants = new
            {
                attendees = new[]
                {
                    new
                    {
                        identity = new
                        {
                            user = new { id = "<object-id>" }
                        },
                        upn = "<upn>"
                    }
                }
            }
        };

        // Use System.Text.Json instead of Newtonsoft.Json
        var jsonContent = JsonSerializer.Serialize(requestBody, new JsonSerializerOptions { PropertyNamingPolicy = JsonNamingPolicy.CamelCase });
        var httpRequest = new HttpRequestMessage(HttpMethod.Post, $"https://graph.microsoft.com/v1.0/users/{organizerUserId}/onlineMeetings")
        {
            Content = new StringContent(jsonContent, Encoding.UTF8, "application/json")
        };

        httpRequest.Headers.Authorization = new System.Net.Http.Headers.AuthenticationHeaderValue("Bearer", token);
        var response = await httpClient.SendAsync(httpRequest);

        if (response.IsSuccessStatusCode)
        {
            var responseContent = await response.Content.ReadAsStringAsync();
            using var doc = JsonDocument.Parse(responseContent);
            return doc.RootElement.GetProperty("joinWebUrl").GetString();
        }
        else
        {
            Console.WriteLine($"Error: {response.StatusCode} - {await response.Content.ReadAsStringAsync()}");
            return null;
        }
    }

    /// <summary>
    /// Gets an access token using Client Credentials Flow.
    /// </summary>
    private static async Task<string> GetAccessToken()
    {
        var options = new ClientSecretCredential(tenantId, clientId, clientSecret);
        var tokenRequestContext = new Azure.Core.TokenRequestContext(new[] { "https://graph.microsoft.com/.default" });
        var accessToken = await options.GetTokenAsync(tokenRequestContext);
        return accessToken.Token;
    }
}

Response:

Reference:

Create and Configure Application Access Policy

Create Online Meetings