Outlook will not refresh

Question

UTC Date: REMOVED PII
Client Id: REMOVED PII
Session Id: REMOVED PII
Client Version: 20260821009.13
BootResult: fail
Back Filled Errors: Unhandled Rejection: SyntaxError: Failed to execute 'json' on 'Response': Unexpected end of JSON input:undefined|undefined:undefined|undefined:undefined|undefined:undefined
err: Error: 401
esrc: StartupData
et: ServerError
estack: Error: 401
 at Object.w [as createStatusErrorMessage] (Microsoft Outlook web script)
 at Microsoft Outlook web script
st: 401
efe: YQBPR0101CA0334
reqid: REMOVED PII
cv: REMOVED PII

Answer 1

PII caution: This is a public user-to-user forum. I have removed some private information from your question to help protect your privacy and security.

I have sent the original version of your question to you in a private message. If you need to provide any additional screenshots or details, please send them there.

Hello Randy,

I understand that Outlook is not refreshing and is showing a startup failure with error 401. This might point to an authentication or sign-in session problem, where Outlook cannot successfully retrieve the account’s startup data.

Could you please confirm:

1. Are you using Outlook on the web, New Outlook for Windows, or the Outlook mobile app?
2. Is this a personal Outlook.com account or a work/school account?
3. Can you access the mailbox from another browser, an InPrivate/Incognito window, or another device?
4. Did the issue begin after a password, security, or account change?

In the meantime, please try signing out of all Microsoft accounts in the browser, closing all browser windows, and then signing in again with only the affected account. If Outlook works in an InPrivate/Incognito window, clear the cookies and cached site data for the Microsoft sign-in and Outlook websites, then test again.

If you are using New Outlook for Windows, you can also close Outlook, open Windows Settings > Apps > Installed apps > Outlook (new) > Advanced options, and try Repair first. If Repair does not help, try Reset, then add the account again.

Please let me know how it goes after trying these steps, and I'll be glad to continue looking into it with you.

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