How to fix
Microsoft Teams error CAA90063
on Windows

I keep getting the error CAA90063 when trying to launch Microsoft Teams on my Windows. I've tried restarting, but the issue persists. What is this error and how can I fix it?

The error code CAA90063 in Microsoft Teams may arise when users attempt to open the application but encounter difficulties in doing so. The complete error message typically states, “We couldn’t sign you in. Please try again later. Error code: CAA90063.” This error may occur for numerous reasons, frequently associated with authentication issues or complications regarding system settings.

There might be more than one reason you are experiencing the CAA90063 error. The most common cause is an issue with your Microsoft account; this could be wrong login details or expired login sessions. Another plausible cause could be a network issue where Teams cannot connect to the relevant servers.

The error can also be related to outdated or corrupted Teams application files, inappropriate system configurations, or some conflict with other third-party applications like virtual private networks (VPNs) or firewalls. The problem could probably be due to an issue resulting from Office 365 or Microsoft's authentication services.

If you encounter the CAA90063 error, then there is a lot you might do to troubleshoot the problem. First of all, make sure your Microsoft account credentials are correct and you have a stable internet connection. If the issue continues to be problematic, check for more advanced solutions through which you could troubleshoot your system's configuration and settings of Teams. Given below are some of the possible solutions that could help you resolve this error.

It is important to systematically try out each solution and find out which one works for your case. Some solutions will immediately set right the problem, while others will involve more work. For a more automatic approach, try running [d1] PC repair app. Either way, applying the right approach is how you'll be able to fix the CAA90063 error and get Teams working.

Fix 1. Check your internet connection

If your internet connection is unstable or disconnected, Teams may fail to authenticate, leading to the CAA90063 error. Ensuring a stable connection is the first step in resolving this issue.

Windows 11

• Type Troubleshoot in Windows search and hit Enter.
• Select Other troubleshooters.
• Locate Network & Internet troubleshooter from the list and click Run.
• Wait till the process is finished and apply the recommended fixes.
• Restart your computer.

Run Network troubleshooter in Windows 10

• Right-click on Start and pick Settings.
• Go to the Network & Internet section.
• On the right side, find the Advanced network settings section.
• Click Network troubleshooter and wait.
• The fixes will be automatically applied.

Fix 2. Sign out and sign back in

Sometimes, simply signing out and signing back into Microsoft Teams can resolve authentication issues, including the CAA90063 error.

• Open Microsoft Teams.
• Click on your profile icon in the top-right corner.
• Select Sign Out.
• Close Teams completely and restart it.
• Sign in again with your correct credentials.

Fix 3. Clear Teams cache

Corrupted cache files can cause various issues with Microsoft Teams, including the CAA90063 error. Clearing the cache can help restore the app's functionality.

• Close down Microsoft Teams.
• Press Win + E to open File Explorer.
• Ensure Hidden files are visible.
• In the address bar, type in %appdata%\Microsoft\teams and press Enter.
• Delete the contents of the following folders:
  %appdata%\Microsoft\teams\application cache\cache
  %appdata%\Microsoft\teams\blob_storage
  %appdata%\Microsoft\teams\Cache
  %appdata%\Microsoft\teams\databases
  %appdata%\Microsoft\teams\GPUcache
  %appdata%\Microsoft\teams\IndexedDB
  %appdata%\Microsoft\teams\Local Storage %appdata%\Microsoft\teams\tmp
• Make sure you empty the Recycle Bin (or use Shift + Del combination to delete these files).
• Restart your system.

Fix 4. Update Microsoft Teams

Outdated app versions can result in various errors, including CAA90063. Ensuring that Teams is up-to-date can fix bugs and compatibility issues.

• Open Microsoft Teams.
• Click on the Settings and more button at the top-right corner.
• Select Check for updates.
• Teams will automatically download and install any available updates.
• Restart Teams after the update is completed.

Fix 5. Disable third-party applications

Third-party applications like VPNs, firewalls, or security software can sometimes interfere with Teams' ability to authenticate. Temporarily disabling these apps can help determine if they're the cause.

• Disable any VPN software that might be running.
• Temporarily turn off your firewall and security software.
• Restart Microsoft Teams and attempt to sign in again.

Fix 6. Reinstall Microsoft Teams

A fresh installation can fix various issues caused by corrupted files or incomplete installations.

• Type Control Panel in Windows search and press Enter.
• Go to Programs > Uninstall a program.
• Find Microsoft Teams, right-click, and select Uninstall.
• Follow the prompts to remove the app.
• Once done, press Win + E to open File Explorer.
• In the View tab at the top of the window, enable Hidden Files.
• Go to C:\Program Files\WindowsApps location.
• Scroll down to find the Microsoft Teams folder and delete it (alternatively, you can rename it).
• Now type %AppData% in Windows search and press Enter.
• Delete the Teams folder here.
• Finally, restart your system and reinstall the app.

Fix 7. Check Microsoft service status

The CAA90063 error may sometimes occur due to problems with Microsoft’s authentication servers. Checking the Microsoft service status can help you determine if the issue is server-side.

• Visit the Microsoft Service Status page.
• Look for any ongoing issues or outages related to Teams or Microsoft services.
• Wait for the server issues to go away.