How do I fix the following error message? Error: 500

Question

Email syncing issues and cannot log in on web

Got the following error on trying to sign in on web:

UTC Date: 2026-01-02T05:01:28.261Z
Client Id: 
Session Id: 
Client Version: 20251212003.10
BootResult: configuration
Back Filled Errors: Unhandled Rejection: Error: 500:undefined|undefined:undefined
err: Microsoft.Exchange.Data.Storage.TenantAccessBlockedException
esrc: StartupData
et: ServerError
estack: Error: 500
    at Object.w [as createStatusErrorMessage]
st: 500
emsg: TenantAccessBlockedError

Answer 1

Dear @Junction Pub & Tourist Park,

Thank you for posting your question in the Microsoft Q&A forum.

According to your description, it means OWA is failing on the server side with TenantAccessBlockedError, which Exchange Online throws when the entire Microsoft 365 tenant is blocked. Here are some steps I recommend you try:

Step 1: Try an InPrivate/Incognito browser

Please try signing in using an InPrivate/Incognito browser window. This helps rule out any cached session or stored credentials that may cause account mix‑ups or sign‑in conflicts.

Open an InPrivate/Incognito window > Go to Outlook for web > Sign in using only the affected work/school account

Step 2: Check and Reassign license

If you are user, I recommend contacting your Microsoft 365 administrator and asking them to check and reassign your license if needed. For more information, please refer to Assign or unassign licenses for users in the Microsoft 365 admin center

• After the license has been reassigned and the subscription is active, the changes take effect shortly.
• Once your admin confirms the license is active, sign out of all Microsoft 365 sessions, close your browser/app, then sign in again to Outlook.

Step 3: Sign in as a Global admin or Billing admin at Microsoft Admin Center, then go to Billing > Bills and payments to clear any overdue balance if one is shown. Next open Billing > Your products, select the Microsoft 365 or Exchange Online subscription, and if you see Suspended or Disabled choose Reactivate subscription and complete the reactivation flow, including updating the payment method if requested.

When the subscription shows Active again, sign out of all Microsoft 365 sessions, close the browser, reopen it, and try Outlook on the web once more.

Note: If you do not have admin rights, please kindly contact your Microsoft 365 administrator because only they can lift a tenant block.

If OWA still shows X-OWA-Error after reactivation, could you please confirm these questions below to help me diagnose the issue more effectively: 

• What status you see for the subscription in Billing > Your products
• Can you sign in to any other Microsoft 365 apps (Teams, OneDrive, Word Online)?
• Whether your Microsoft 365 license is still active?
• Does the error appear only on Outlook on the web, or also in Outlook desktop/mobile apps?
• Are you the Microsoft 365 administrator for your organization, or do you have someone else managing licenses and billing?
• Have you recently switched between multiple accounts (personal vs work) on the same browser?

Note: Please understand that as forum moderator, my primary goal is to provide helpful guidance and support through general troubleshooting steps. While I don’t have access to internal systems or test devices required to resolve backend issues, I truly appreciate your understanding of these limitations. I genuinely hope the information I share helps guide you in the right direction, and I'm always here to assist as much as I can within my scope.  

I hope this information is helpful. Please follow these steps and let me know if it works for you. If not, we can work together to resolve this. If I misunderstand anything, please feel free to reach out.

Please understand that the initial response does not always resolve the issue immediately. However, with your help and more detailed information, we can work together to find a solution.

Thank you for your patience and your understanding. If you have any questions, please feel free to reach out.

I'm looking forward for your reply.

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Answer 2

Dear @Junction Pub & Tourist Park,

Thank you for your update. Since the error appears both in your browser and in the Outlook apps, this confirms the issue is not caused by your device. The message TenantAccessBlockedError / TenantAccessBlockedException means that your organization’s Microsoft 365 tenant is currently blocked at the service level

However, you said that you had admin rights until 23/12/2025, so I understand that now you cannot access to the Microsoft Admin Center.

First, please check whether anyone else in your company still has Global Admin or Billing Admin access. If another admin exists, please ask them to check the Billing and License in the Microsoft 365 Admin Center. Moreover, the Global Admin can also create a service request with Microsoft support to get advanced technical assistance and diagnostics. For detailed instructions on how to get support, please refer to Get support - Microsoft 365 admin.      

If no one in the organization currently has admin access, you will need Microsoft Support to help restore it. They can verify your domain ownership and business information and help restore the Global Admin role to the correct person. ​‌Here are some options I recommend you try:  

Option 1: Contact Microsoft Support by Phone

If you are the only administrator and are locked out, the most direct method is to call Microsoft's support line to raise a request for getting back access. For a full list of regional numbers, you can also visit this official page: Customer service phone numbers - Microsoft Support. The support team will assist you as soon as possible. For reference:  Get support | Microsoft Docs   

Note: If you’re an end-user, please coordinate with your Office 365 Global Administrator to handle these steps. 

Option 2: Create a Temporary Account (Trial Tenant) to Submit a Support Ticket

If you have difficulty reaching an agent by phone, there is a reliable workaround. This involves creating a new, temporary Microsoft 365 account to contact the support team online. 

• Sign up for a new Microsoft 365 Business trial using this link: Compare All Microsoft 365 Plans. You will need to use a different, personal email address to register. 
• Once the trial account is created, log in to its Admin Center. 
• From the Admin Center, open a new Service Request. For reference:  Get support | Microsoft Docs   
• In the ticket description, explain that you are locked out of your primary tenant (your.onmicrosoft.com) and that you need to speak with the Data Protection team to regain access. Provide your locked account's details and a good contact number for them to reach you. 

Important: Please remember to cancel the trial subscription after your original account issue is resolved to avoid any future charges. 

I apologize for redirecting you the related team support, please understand that as forum moderator, my primary goal is to provide helpful guidance and support through general troubleshooting steps. While I don’t have access to internal systems or test devices required to resolve backend issues, I truly appreciate your understanding of these limitations. I genuinely hope the information I share helps guide you in the right direction, and I'm always here to assist as much as I can within my scope.  

I hope this information is helpful. Please follow these steps and let me know if it works for you. If not, we can work together to resolve this. If I misunderstand anything, please feel free to reach out.

Thank you for your patience and your understanding. If you have any questions, please feel free to reach out.

I'm looking forward for your reply.

---

If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".   

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

Answer 3

The error message you are encountering, specifically TenantAccessBlockedException, indicates that the tenant (your organization's account) has been blocked from accessing certain services. This could be due to various reasons such as billing issues, compliance issues, or account restrictions.

To resolve this issue, consider the following steps:

1. Check Account Status: Ensure that your Microsoft 365 account is active and in good standing. Log in to the Microsoft 365 admin center to check for any alerts or notifications regarding your account.
2. Billing Issues: Verify that there are no outstanding invoices or payment issues. If there are, resolve them as soon as possible.
3. Contact Support: If you are unable to identify the issue, contact Microsoft support for assistance. They can provide specific details regarding the tenant access block and guide you on how to resolve it.
4. Check for Compliance Issues: Ensure that your organization is compliant with Microsoft’s policies, as non-compliance can lead to access being blocked.

Following these steps should help you address the error and regain access to your email and other services.