Microsoft Teams: Can't Sign In or Login Loop

If Microsoft Teams keeps asking you to sign in, shows a login loop, or gives an authentication error, here's how to fix it. Step 1: Clear the Teams cache The Teams cache can get corrupted and cause sign-in failures. 1. Completely quit Teams (right-click the icon in the taskbar > Quit) 2. Press Win + R, type %appdata%\Microsoft\Teams and press Enter 3. Delete all files and folders inside that Teams folder (don't delete the folder itself) 4. Reopen Teams and sign in Step 2: Sign out and sign in with the correct account When Teams opens, make sure you're signing in with your full work email address (e.g. [email protected]), not a personal Microsoft account. Step 3: Try Teams on the web Go to teams.microsoft.com in your browser and sign in there. If web Teams works but the desktop app doesn't, the issue is with the local installation. Step 4: Remove saved Windows credentials 1. Open Credential Manager (search in Start menu) 2. Click Windows Credentials 3. Remove any credentials related to Teams or Microsoft Office 4. Restart Teams Step 5: Reinstall Teams 1. Go to Settings > Apps and uninstall Microsoft Teams 2. Also uninstall "Teams Machine-Wide Installer" if you see it 3. Restart your computer 4. Download and install Teams fresh from teams.microsoft.com Contact us at (269) 261-0269 if you're still unable to sign in.