Fix Microsoft Outlook and Teams Error 80090016 Sign-In Failure
Question details
Users are experiencing sign-in failures in Microsoft Outlook and Teams, accompanied by error code 80090016, blocking access to their accounts.
- Product
- Microsoft Outlook and Teams
- Device & OS
- Windows
- Scenario
- Attempting to sign in to Microsoft Outlook or Teams desktop applications using a Windows work or school account.
- Observed behavior
- The application fails to authenticate the user and displays error code 80090016, preventing access to emails, chats, and other Microsoft 365 services.
Ensure you have administrative privileges on your Windows computer, as modifying credential and account settings requires elevated permissions. Save any ongoing work and completely close all Microsoft Office applications before proceeding.
Disconnect Work/School Account and Clear Windows Credentials
Removing corrupted credentials and re-adding your work or school account is the most effective way to resolve authentication error 80090016.
This error is commonly caused by a mismatch or corruption in the cached authentication tokens stored on your Windows device. Clearing these credentials forces the system to generate a fresh, working token.
Open Windows Settings, navigate to 'Accounts', and select 'Access work or school'. Find the problematic account, click on it, and select 'Disconnect'.
Press the Windows key, type 'Credential Manager' in the search bar, and press Enter to launch the utility.
Click on 'Windows Credentials'. Scroll down to 'Generic Credentials' and look for any entries related to Microsoft Office, Outlook, or Teams. Click the drop-down arrow next to each and select 'Remove'.
Restart your computer. Open Outlook or Teams and sign in again to re-establish a fresh, secure connection.
Reset Microsoft AAD Broker Plugin and Teams Settings
If clearing credentials does not work, the underlying Azure Active Directory (AAD) authentication folders or Teams cache may be corrupted and require a manual reset.
Test with a New Windows User Profile
When the current user profile is deeply corrupted, creating a new local profile can bypass the damaged registry and app data causing the 80090016 error.
Avoid Complex Authentication Errors with WPS Office
Tired of dealing with frustrating sign-in errors like 80090016 in Microsoft 365? WPS Office provides a lightweight, highly compatible, and free alternative to Microsoft Office. It allows you to create, edit, and manage Word, Excel, and PowerPoint files without relying on complex cloud authentication protocols.
- 1. Download the Installer: Visit the official WPS Office website and download the free installer for your operating system.
- 2. Install the Software: Run the downloaded file and follow the quick, lightweight installation wizard.
- 3. Open Your Files: Launch WPS Office and instantly open your existing Microsoft Office documents without any sign-in roadblocks.
Frequently Asked Questions
What does error code 80090016 mean in Microsoft 365?
Error 80090016 generally indicates that the Trusted Platform Module (TPM) has malfunctioned or the authentication tokens for your Azure Active Directory (AAD) account have become corrupted, preventing a successful sign-in.
Can a Windows update cause Outlook error 80090016?
Yes, major Windows system updates, motherboard replacements, or unexpected password changes can corrupt the secure token cache stored in your device's Credential Manager, triggering this error across Office apps.
Will I lose my emails if I clear the Teams and Outlook cache?
No. Clearing the application cache or deleting Windows credentials only removes local temporary authentication data. Your emails, chats, and actual files remain safely stored and synced on Microsoft's cloud servers.
Do I need an IT administrator to fix this issue?
While many individual users can resolve it by clearing their Windows credentials or reconnecting their work/school account, you may need to contact your IT admin if your organization has strict device management policies blocking local credential modifications.
