Unable to log into my Teams account though having chatted with two agents

Hi @Joze Bannister,

Welcome to the Microsoft Q&A forum.

I would like to share the following information with you:

Please follow the steps below and check whether the issue has been resolved:

1. Perform an Online Repair for Office:

Step 1: Close all Office applications

Step 2: Press Windows + I

Step 3: Go to Apps > Installed apps, then locate your Office suite

Step 4: Click the … > Modify > Online Repair

2. Uninstall and reinstall the Office suite
3. Clear credentials:
   1. Please sign out of your account from all Office applications, then close all Office apps
   2. Open File Explorer, paste the following path, and delete all files/folders: %localappdata%\Packages\Microsoft.AAD.BrokerPlugin_cw5n1h2txyewy
   3. Open your browser, press Ctrl + Shift + Delete, then select Clear now
   4. Go to Settings > Accounts > Access work or school
   5. Check whether your account appears under Access work or school:
      • If yes, select the account and click Disconnect
      • Then click Connect and sign in again to re-register the device
   6. Clear cached credentials:
      • Open Control Panel
      • Go to User Accounts > Credential Manager
      • Under both Windows Credentials and Generic Credentials, locate any entries related to your Microsoft 365 account
      • Select and remove those entries
      • Restart your computer, then try signing in to Office again

Download and run OLicenseCleanup.vbs This tool helps remove licenses, cached identities in the HKCU registry, and stored credentials.

For more details, you can refer to the article: Reset Microsoft 365 Apps for enterprise activation state

• Restart your device
• Reopen Office applications and sign in with the correct account

I hope this information is helpful. Please follow these steps and let me know if it works for you. If not, we can work together to resolve this.   

Thank you for your patience and your understanding. If you have any questions or need further assistance, please feel free to share them in the comments on this post so I can continue to support you.

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

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The error message indicates a sign-in/access issue affecting Microsoft 365 apps (Teams, Outlook, Word) after a Windows update. Similar issues in the context were either temporary service problems or were fixed by installing a specific Windows update.

Follow these steps on the affected PC:

1. Restore Teams access
   1. Open Teams.
   2. If a Sign in banner appears, select it and complete the sign-in (including any MFA prompts).
   3. If no banner appears, check the notification area (system tray) near the clock for a Teams icon with a dot or exclamation mark and select it to open the sign-in window.
   4. If the sign-in window does not open, right-click the Teams icon in the notification area, select Quit, then reopen Teams and sign in again.
   5. Ensure the required network/VPN is connected before opening Teams and avoid switching networks while Teams is running.
2. Check for temporary service issues
   • In similar cases, users were temporarily blocked (for example, TenantAccessBlockedError) and access started working again after waiting 20–30 minutes. If this is a transient service-side issue, retry sign-in periodically.
3. Verify Windows updates (for Microsoft 365 sign-in issues)
   • Go to Settings → Windows Update and check if any pending updates are available.
   • Specifically, if update KB5085516 is available, install it and restart the device. This update was released to fix Microsoft account sign-in issues in some apps caused by a previous update.
4. If sign-in is still blocked
   • Because Teams and other Microsoft 365 apps rely on modern authentication and organizational policies, there may be a problem with the organization’s tenant or security configuration.
   • Contact the organization’s IT admin or Microsoft 365 admin and provide them with:
     • The error message and code shown when signing into Teams/Outlook.
     • The date/time the issue started (after the Windows update).
   • The admin may need to check for tenant-level blocks or policy changes that affect sign-in.

If, after installing all Windows updates and following the sign-in steps, Teams still cannot connect while other apps are also failing, the issue is likely with the Microsoft 365 tenant or account configuration and must be resolved by the IT admin or Microsoft support.

References:

• Why am I having trouble signing in to Microsoft Teams?
• Restore your access to Microsoft Teams
• Restore your access to Microsoft Teams Free
• Teams will always log into the domain-joined PC account
• MS365 products not signing in as even when internet connection is available - Microsoft Q&A
• Tried loggin into Teams and Outlook and got this message on outlook, and unable to log into teams. - Microsoft Q&A
• I have issue signing in to my microsoft office account. - Microsoft Q&A