How to fix microsoft outlook error with Sign in via browser

Question

No matter what I do, each day after a few hours of work, my outlook will randomly say I need to Sign In Via Browser and after I do, Microsoft Edge says that I am authenticated and to close the browser, but the error remains. How do I stop this error

Answer 1

Hi Ben Green 

I hope you are doing well ! I just want to check if you have had a chance to test the steps earlier? Please let me know if they helped resolve the issue or if you are still experiencing any difficulties. I am here to assist you further.

Best Regards

Answer 2

Dear Ben Green 

Thank you for reaching out to the Microsoft Q&A Community. I understand that Classic Outlook for Windows (home use) intermittently shows “Sign in via browser”, Edge confirms authentication, but Outlook keeps prompting. Please follow these steps:  

1) Ensure Outlook Uses Modern Authentication with Outlook.com Sync  

If the account is added as POP/IMAP, remove it and re‑add the account using Outlook’s native Outlook.com provider so OAuth is used. POP/IMAP will continue to re‑prompt because Basic Authentication has been retired.  

2) Run the Classic Outlook Authentication Troubleshooter  

Open Get Help > Classic Outlook troubleshooters and run the Authentication check (and if prompted, Connectivity). Apply any fixes offered, then restart Outlook. See: Classic Outlook troubleshooters – Microsoft Support.  

3) Sign Out of Office Completely, Then Sign In Again  

In Outlook, go to File > Office Account > Sign out. Close all Office apps, reopen Outlook, and sign back in with your Microsoft account. This resets the Office identity token used by Outlook.  

4) Repair Windows Web Account Manager (WAM) / AAD Broker Plugin  

This step fixes “browser sign‑in but client not updated” loops. Open PowerShell (Run as user) and execute:  

Code  

Add-AppxPackage -Register "$env:windir\SystemApps\Microsoft.AAD.BrokerPlugin_cw5n1h2txyewy\Appxmanifest.xml" -DisableDevelopmentMode -ForceApplicationShutdown        Add-AppxPackage -Register "$env:windir\SystemApps\Microsoft.Windows.CloudExperienceHost_cw5n1h2txyewy\Appxmanifest.xml" -DisableDevelopmentMode -ForceApplicationShutdown       

These commands re‑register the identity components Outlook relies on after the browser completes authentication.  

5) Let Windows Auto‑Repair a Missing AAD Broker (If Applicable)  

Windows includes an Access work or school troubleshooter that auto‑installs Microsoft.AAD.BrokerPlugin when missing. Verify it ran under Settings > System > Troubleshoot > Recommended troubleshooter history. See: Access work or school troubleshooter for restoring access to M365 desktop applications – Microsoft …  

6) Repair the Outlook Mail Profile  

In Outlook: File > Account Settings > Account Settings > select your account > Repair. If issues persist, create a new profile via Control Panel > Mail > Show Profiles and re‑add the account (using the Outlook.com provider).  

7) Remove Stale Saved Credentials  

Open Credential Manager (Windows Search), review Windows Credentials and Web Credentials for old Microsoft/Office entries, remove stale ones, then sign in again.  

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

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