How to fix this outlook login error

DEBY ELYA MIRANDA 0 Reputation points
2026-08-15T09:21:42.86+00:00 
UTC Date: 2026-08-15T09:18:10.991Z
Client Id: [Moderator note: Personally Identifiable Information removed]
Session Id: [Moderator note: Personally Identifiable Information removed]
Client Version: 20260807011.11
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
    [Moderator note: Personally Identifiable Information removed]/owa.mailindex.d2af94e2.js:1:190523
st: 500
ehk: X-OWA-Error
efe: [Moderator note: Personally Identifiable Information removed]
ewsver: [Moderator note: Personally Identifiable Information removed]
reqid: [Moderator note: Personally Identifiable Information removed]
cv: [Moderator note: Personally Identifiable Information removed]
Outlook | Web | Outlook on the web for business | Sign in
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  1. Julie Huynh 3,080 Reputation points Independent Advisor
    2026-08-15T09:44:56.3333333+00:00

    Dear @DEBY ELYA MIRANDA,

    Good day! Welcome to Microsoft Q&A forum!

    Based on the error message “Microsoft.Exchange.Clients.Owa2.Server.Core.OwaUserHasNoMailboxAndNoLicenseAssignedException” you received, indicates that this is a license issue. It could be that the admin has not assigned an Exchange online license to your account yet, or in some cases, it could be that your admin has changed in license settings lately.

    If you are an end user, please kindly ask your IT administrator to check your account in the Microsoft 365 Admin Center. Then go to Users > Active users, select your username, then open Licenses and apps. Under the Apps section, please make sure that Exchange Online (Plan 1 or Plan 2) is enabled.  User's image

    User's image

    If it is already enabled, the admin can uncheck it, save, then re‑enable it again and wait for the sync period. This often forces the mailbox provisioning to refresh and may resolve the error you're seeing. 

    If you do not have admin privileges, contacting your organization’s IT admin is the quickest way to proceed since only they can verify and adjust these settings. You can read the article "How do I find my Microsoft 365 admin?" to find your admin.

    For reference, you may also review this article: Getting a mailbox not found error in Outlook on the web - Microsoft 365 admin | Microsoft Learn 

    I hope this information is helpful. Kindly let me know when there are updates or if you need further assistance. Any updates you’re able to share would be really helpful. I appreciate your time and look forward to hearing how things are going!

    Thank you for your time and patience.

    If the answer is helpful, please kindly click "Yes" on the post. If you have extra questions about this answer, please click "Comment".

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