getting error while accessing outlook, teams and excel

Dear @Rajendra Vaishnava,
Welcome to Q&A forum. I understand that when you try to sign in to Outlook, Teams, and Excel on your Windows device, you receive the error “A required authentication broker is missing,” which is preventing you from accessing Microsoft 365 desktop apps.

To better assistance, could you please confirm the following:

Does this error appear only in Outlook, Teams, and Excel, or does it affect all Microsoft 365 desktop apps?

Are you able to sign in successfully using Outlook on the web or Teams on the web?

When did this issue first start? Did it begin after a Windows update, Office update, or device change?

Does the issue occur on only this device, or have you tested the same account on another Windows device?

Is this device managed by your IT administrator?

Have you recently changed your password or completed any multi‑factor authentication (MFA) prompts?

In the meantime, please try the following:

Restart your computer

Make sure Windows is fully updated

Make sure Microsoft 365 apps are up to date

Please understand that our initial response does not always resolve the issue immediately. However, with your help and more detailed information, we can work together to find a solution.

I truly appreciate your patience and understanding. If you have any further questions or need further clarification, please feel free to reach out. I'm looking forward to hearing from you. 

Thank you for your cooperation.

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The error indicates an issue with the Windows authentication broker (WAM/AAD.BrokerPlugin), which is required for signing in to Microsoft 365 apps like Outlook, Teams, and Excel.

Follow these steps on the affected Windows device:

1. Reboot the device
   • Restart Windows and try signing in again to Outlook/Teams/Excel.
2. Repair the WAM components via PowerShell (user mode)
   • Close all Office apps (Outlook, Teams, Excel, Word, etc.).
   • Open PowerShell as the signed-in user (not necessarily as admin).
   • Run these commands one by one:

          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
     

   • After the commands complete, restart the device again and test sign-in.
3. Check for security software interference
   • Security software can block or break the WAM plug-in (AAD.BrokerPlugin) and cause sign-in failures.
   • Temporarily uninstall (not just disable) any third‑party security/AV/endpoint protection software.
   • Reboot and test sign-in again.
   • If this resolves the issue, coordinate with the security/IT team to adjust policies or exclusions so AAD.BrokerPlugin and CloudExperienceHost are not blocked.
4. If using roaming profiles/VDI
   • Ensure that no data under %localappdata% related to identity is being roamed. Profile tools must exclude at least these paths/keys:
     1. %localappdata%\Packages\Microsoft.AAD.BrokerPlugin_cw5n1h2txyewy
     2. %localappdata%\Packages\Microsoft.Windows.CloudExperienceHost_cw5n1h2txyewy
     3. %localappdata%\Packages\<any app package>\AC\TokenBroker
     4. %localappdata%\Microsoft\TokenBroker
     5. HKEY_CURRENT_USER\SOFTWARE\Microsoft\IdentityCRL
     6. HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\AAD
     7. HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows NT\CurrentVersion\WorkplaceJoin
   • Roaming the work account device certificate (MS‑Organization‑Access) is not supported and can also break authentication.
5. Update Microsoft 365 Apps
   • Make sure Office is updated to a version that includes recent sign‑in fixes (e.g., Office Version 2310 Current Channel or 2309 MEC, as applicable in the environment).
6. Temporary workaround
   • Until the issue is fully resolved, use Outlook on the web (OWA), Office web apps, or mobile apps to access mail and documents.
7. If the issue persists in a tenant environment
   • Ask the Microsoft 365 tenant admin to open a support ticket from the Microsoft 365 Admin Portal.
   • Before opening the ticket, completely uninstall any security software and collect MSOAID logs as described in Use MSOAID for authentication issues, then attach them to the support request.

References:

• Error “Something Went Wrong [1001]” signing in to Microsoft 365 Desktop Applications
• Error “Something Went Wrong [1001]” signing in to Microsoft 365 Desktop Applications