How to fix log-in issues; UTC Date: 2025-08-02T09:26:47.714Z Client Id: B0DAD20B7F6140FC840AF19FADDC8931 Session Id: f9b1e39d-fd29-462b-9da9-f10acf851aa9 Client Version: 20250725003.04 BootResult: configuration Back Filled Errors: Unhandled Rejection: Err

Hello Adebayo Olufela,

Welcome to Microsoft Q&A!

Thank you for your post. I understand that you are having log-in issues. I truly understand how you feel. Let me assist you go through this situation.

For me to provide you the most accurate solution, could you clarify a few things:

Where are you seeing the log-in issue? Is it happening in the Office desktop apps, Office Online (browser), or Microsoft 365 admin portal?

What exactly happens when you try to log in? Do you get an error message like “Something went wrong,” a blank screen, or does it just hang?

Is this affecting just one device or multiple devices? If multiple, are they all on the same network or using VPN?

Have you recently changed your password or renewed your license? This can sometimes cause credential mismatches.

Once I have these details, I can guide you through the most relevant fix steps or escalate it if needed.

I am looking forward for your respond. Thank you so much for your times.

Best Regard,

Katerina- MSFT | Microsoft Q&A Support Specialist

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Hello Adebayo Olufela,

Thank you for your post.

I haven't received any further update from you yet. If there is anything more that I could do for you or if anything is unclear that I can assist you with. Please do not hesitate to let me know.

Best Regards,

Katerina- MSFT | Microsoft Q&A Support Specialist

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. 

UTC Date: 2025-08-08T08:40:22.304Z
Client Id: EFC8D806857C4DAC8C3AB206EBAC081F
Session Id: 99fc1be2-772e-4932-ace3-c30a8e70dc60
Client Version: 20250801002.03
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.78420113.js:1:1041)
    at https://res.public.onecdn.static.microsoft/owamail/hashed-v1/scripts/owa.mailindex.78420113.js:1:164077
st: 500
ehk: X-OWA-Error
efe: PN4P287CA0125
emsg: UserHasNoMailboxAndNoLicenseAssignedError

UTC Date: 2025-09-30T01:01:02.314Z
Client Id: 0522B3D73B474FB083E030A81B88B28E
Session Id: cbc51117-2bde-4a56-a91b-1fe21d71a0e8
Client Version: 20250918044.08
BootResult: fail
Back Filled Errors: Unhandled Rejection: Error: 440:undefined|undefined:undefined
err: Error: 440
esrc: StartupData
et: ServerError
estack: Error: 440
    at Object.w [as createStatusErrorMessage] (https://res.public.onecdn.static.microsoft/owamail/hashed-v1/scripts/owa.mailindex.b6142b89.js:1:3671)
    at https://res.public.onecdn.static.microsoft/owamail/hashed-v1/scripts/owa.mailindex.b6142b89.js:2:22164
st: 440
efe: BL1PR13CA0364