我们无法识别此租户ID 21f3be0a-713c-4b7f-ab75-3cc5ca25846。请仔细检查租户ID,然后重试。",

你可以 check whether a tenant is valid or invalid 使用众所周知的OpenId配置端点:

https://login.microsoftonline.com/<tenant>/.well-known/openid-configuration

对租户id执行此操作会得到以下结果:

https://login.microsoftonline.com/21f3be0a-713c-4b7f-ab75-3cc5ca25846/.well-known/openid-configuration

错误

错误描述 :“AADSTS90002:承租人 未找到21f3be0a-713c-4b7f-ab75-3cc5ca25846。如果 租户没有活动订阅。与您的 订阅管理员。\r\n轨迹ID: bdd561b1-bc36-44ce-b3ab-33e53fda0100\r\n相关ID: c6ce0c0d-6550-4f5f-a398-a82f085e28c1\r\n时间戳:2017-11-01

简单地说,您使用的租户id对于AAD Worldwide端点无效。

您是否可能正在为不同的AAD实例获取令牌?你能分享一下吗 contents of your Access Token

   I did some mistakes thats why this Error raised then need not do anything becoz this Portal app by default Multitenant and send request to common platform ..
    Login with other tenant get code

    https://login.microsoftonline.com/common/oauth2/authorize?
    client_id=XXXXX-XXX
    &response_type=code
    &redirect_uri=http://localhost:49876    
    &response_mode=query
    &scope=Reports.Read.All 
    &prompt=consent
    &state=12345


    then get token 
    https://login.microsoftonline.com/common/oauth2/token
    client_id =XXX
    scope =
    code= which you get
    grant_type=
    client_secret=

    after get token use for Graph API & get office365 data for -https://graph.microsoft.com/beta/reports/getMailboxUsageMailboxCounts(period='D7')