Fix Teams error 2026

A Professional Guide to Resolving Microsoft Teams Error 2026

Microsoft Teams Error 2026 is a common authentication-related issue that prevents users from signing in or remaining signed in. The error typically indicates that the Teams client is unable to acquire or refresh a necessary authentication token from Microsoft's services. This can be caused by a variety of factors, including a corrupted cache, incorrect system time, network configuration, or restrictive enterprise policies. This guide provides a series of comprehensive technical solutions to diagnose and fix Error 2026.

Solution 1: Basic Troubleshooting Steps

Before proceeding to more complex solutions, perform these initial steps, as they can often resolve transient authentication glitches.

• Sign Out and Sign In: Manually sign out of your Teams account completely. Click on your profile picture, select "Sign out," and then close the application. Relaunch Teams and attempt to sign in again.
• Restart the Application: Ensure Microsoft Teams is fully closed. Right-click the Teams icon in your system tray (bottom-right corner of the screen) and select "Quit." Wait for about 30 seconds before reopening the application.
• Reboot Your Computer: A full system restart can clear temporary system state issues and network connection problems that might be contributing to the error.

Solution 2: Clear the Microsoft Teams Cache

A corrupted cache is one of the most frequent causes of Teams authentication errors. The application stores temporary data, including authentication tokens, which can become invalid or corrupt. The cache location differs between the "Classic" and "New" Teams clients.

For the Classic Teams client:

• Fully quit Microsoft Teams by right-clicking the icon in the system tray and selecting "Quit."
• Open the Run dialog box by pressing Windows Key + R.
• Type %appdata%\Microsoft\Teams and press Enter.
• In the folder that opens, delete all files and subfolders. Do not worry; this will not delete your chats or files, which are stored in the cloud.
• Restart Microsoft Teams. It will rebuild the cache, and you will be prompted to sign in.

For the New Teams client:

• Fully quit the New Teams client.
• Open File Explorer.
• Navigate to the following path: C:\Users\%username%\AppData\Local\Packages\
• Locate the folder that starts with MSTeams_ or MicrosoftTeams_ followed by a random string (e.g., MSTeams_8wekyb3d8bbwe).
• Open this folder and delete all its contents.
• Restart the New Teams client and sign in.

Solution 3: Verify System Date and Time Settings

Authentication protocols like OAuth 2.0 rely on synchronized time between the client and the server. If your computer's date, time, or time zone is incorrect, it can cause token validation to fail, resulting in Error 2026.

• Right-click the clock on your taskbar and select "Adjust date/time."
• Ensure that "Set time automatically" and "Set time zone automatically" are both enabled.
• If they are already on, toggle them off and then on again to force a re-sync with the time server.
• Go to the "Sync now" button under "Additional settings" and click it to ensure your system time is accurate.

Solution 4: For IT Administrators - Review Conditional Access Policies

In a corporate environment, Error 2026 may not be a client-side issue but rather a result of a security policy configured in Microsoft Entra ID (formerly Azure Active Directory). Conditional Access policies can block sign-in attempts that do not meet specific criteria.

• Check Entra ID Sign-in Logs: An administrator should review the user's sign-in logs in the Microsoft Entra admin center. The logs will provide a detailed reason for any failed authentication attempt, specifying which policy caused the block.
• Verify Policy Requirements: The policy might require the device to be compliant (e.g., managed by Intune), be hybrid-joined, or be connecting from a trusted IP address. The error can occur if the user's device or location does not meet these conditions.
• Multi-Factor Authentication (MFA): Ensure there are no issues with the user's MFA configuration that could be silently failing the token acquisition process.