Tried loggin into Teams and Outlook and got this message on outlook, and unable to log into teams.

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Tried loggin into Teams and Outlook and got this message on outlook, and unable to log into teams.

B S 20

UTC Date: 2026-03-17T13:16:25.202Z

Client Id: [Moderator note: personal information removed]

Session Id: [Moderator note: personal information removed]

Client Version: 20260306001.05

BootResult: configuration

Back Filled Errors: Unhandled Rejection: Error: 500:undefined|undefined:undefined

err: Microsoft.Exchange.Data.Storage.TenantAccessBlockedException

esrc: StartupData

et: ServerError

estack: Error: 500at Object.w [as createStatusErrorMessage] ([Moderator note: personal information removed]) at [Moderator note: personal information removed] st: 500

ehk: X-OWA-Error

efe: [Moderator note: personal information removed]

ewsver: [Moderator note: personal information removed]

emsg: TenantAccessBlockedError

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Answer 1

The error TenantAccessBlockedException / TenantAccessBlockedError with HTTP status 500 indicates that access to the Microsoft 365 tenant is blocked at the service level. This is a tenant-side issue, not a client configuration problem on the device.

Because tenant access is blocked, sign-in and data access for Outlook and Teams will fail until the block is removed by Microsoft 365 service or by tenant administration through a support case.

Action steps:

Contact the Microsoft 365 tenant administrator
- The admin must sign in to the Microsoft 365 Admin Center and check the tenant health and service status.
- If the admin also cannot access services, they should use the Admin Center support entry points or phone support to open a service request with Microsoft.
Open a support ticket from the tenant
- The admin should open a support ticket in the M365 Admin Portal describing that users receive TenantAccessBlockedException when accessing Outlook on the web and cannot sign in to Teams.
- Include time of occurrence, affected users, and any correlation IDs from the error details.
If sign-in issues to desktop apps also appear
- For broader sign-in failures to Microsoft 365 desktop apps, the admin should follow the guidance under “Can’t sign in to Microsoft 365 desktop applications” and related authentication troubleshooting, and may be asked by Microsoft Support to collect MSOAID logs as described in Use MSOAID for authentication issues.
Do not attempt client-only fixes
- Local repairs (reinstalling Outlook/Teams, clearing caches, etc.) will not resolve a tenant-level block. Resolution requires Microsoft 365 service-side or billing/compliance remediation coordinated by the tenant admin and Microsoft Support.

Until the tenant block is cleared, Outlook on the web, new Outlook for Windows, and Teams sign-in will continue to fail with tenant access errors.

References:

Answer 2

B S 20

My issue turned out to be temporary, as I waited for roughly 30 minutes and was able to log in on both Teams and Outlook.

Liora D 13,760 Reputation points Microsoft External Staff Moderator

2026-03-17T14:14:47.4633333+00:00

Hi B S,**
**Thank you for the update. I'm glad to hear that the issue was temporary and that you’re now able to access both Microsoft Teams and Outlook without any further problems.

Answer 3

Dear @B S,

Thank you for reaching out and for sharing the detailed error information. To better understand the situation and provide you with the most relevant guidance, we would need a bit more information from your side.

First, may I kindly ask you to double‑check with your Microsoft 365 administrator whether your account still has an active license assigned, specifically for Exchange Online.

To verify this, please sign in to the Microsoft 365 Admin Center at https://admin.microsoft.com using an admin account. From there, go to Users > Active users, select your user account, then open Licenses and apps. Under Apps, please make sure that Exchange Online (Plan 1 or Plan 2) is enabled. If the license is already assigned, you may try unchecking Exchange Online, saving the change, and then re‑assigning it. After that, allow some time for synchronization and check whether the issue persists.

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If you do not have administrator privileges, please contact your organization’s Microsoft 365 administrator and ask them to perform the above checks on your behalf.

You may also find the following Microsoft article helpful, as it covers similar mailbox‑related access issues in Outlook on the web: Getting a mailbox not found error in Outlook on the web – Microsoft Learn.

If the issue still occurs after confirming the license assignment, the next recommended step is to raise a support request directly with Microsoft. Using an admin account, please go to the Microsoft 365 Admin Center, then navigate to Support > New service request. The support engineers handling these tickets have the appropriate escalation channels and backend visibility, which makes this the most efficient way to investigate tenant‑level or service‑side issues. You can refer to this article for guidance on how to open a support ticket: Ways to contact support for business products – Admin Help.

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I hope this information helps point you in the right direction. If you run into any issues while trying the steps, or if something still doesn’t feel quite right, please don’t hesitate to reach out again. I’ll do my best to support you however I can.

Looking forward to hearing back from you with any updates or additional details.

Warm regards,

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Tried loggin into Teams and Outlook and got this message on outlook, and unable to log into teams.

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