How to fix issue with Outlook

Question

How to fix issue with Outlook

Thomas Cowling 0

Whenever I try to log in to Microsoft Outlook on my PC or Laptop it stops me and brings up this error page that says:

UTC Date: 2026-08-28T21:17:11.238Z
Client Id: 
Session Id: 
Client Version: 20260821009.08
BootResult: configuration
Back Filled Errors: Unhandled Rejection: Error: 500:undefined|undefined:undefined
err: Microsoft.Exchange.Clients.Owa2.Server.Core.OwaUserHasNoMailboxAndNoLicenseAssignedException
esrc: StartupData
et: ServerError
estack: Error: 500
    at Object.w [as createStatusErrorMessage] (https://res.public.onecdn.static.microsoft/owamail/hashed-v1/scripts/owa.mailindex.491fdc82.js:1:806)
    at https://res.public.onecdn.static.microsoft/owamail/hashed-v1/scripts/owa.mailindex.491fdc82.js:1:192762
st: 500
ehk: X-OWA-Error
efe: CH0PR03CA0200
ewsver: 15.21.339.12
reqid: 
cv: vdBnE3B+tXilRUo9gwpIJX.0.1.1

How do I fix this so that I can access Outlook on my Pc and Laptop

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1 answer

Your answer

Answer 1

Hi Thomas,

Based on the logs you provided, the error is: Microsoft.Exchange.Clients.Owa2.Server.Core.OwaUserHasNoMailboxAndNoLicenseAssignedException

Error 500: UserHasNoMailboxAndNoLicenseAssignedError

This error typically occurs when the account does not have an Exchange Online mailbox assigned or the account is missing the required Microsoft 365 license that includes Exchange Online services. Without a mailbox and proper licensing, Outlook on the web cannot load your mailbox data, which results in this error.

This issue requires administrative action and cannot be fixed by an end user. Please contact your IT administrator and ask them to:

Ensure your account has a valid Microsoft 365 license that includes Exchange Online (e.g., Microsoft 365 Business Standard, E3, or E5).
In the Microsoft 365 Admin Center, navigate to Users > Active Users > [Your Account] > Licenses and Apps and check that Exchange Online is enabled.
If not, assign the appropriate license. They can also unassign and reassign the license to reactivated it.
The reactivated process may take up to 24 hours to finalize.

Then I'd suggest the admin verify your mailbox existence by using PowerShell:

Get-Mailbox -Identity ******@domain.com

If no mailbox exists, create one:

New-Mailbox -UserPrincipalName ******@domain.com -FirstName 'First' -LastName 'Last'

Please try to open Outlook via Outlook Web Access (OWA) in an incognito mode to see if you're able to use it after ensuring the mailbox and license are correctly configured.
I hope this provides enough clarity and helps you stay inform with your current situation.

Thank you for your patience and your understanding. If you have any questions or need further assistance, please feel free to share them in the comments on this post so I can continue to support you.

If the answer is helpful, please click 'Yes' and kindly upvote it.

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