HomeFixesFix Microsoft Teams Login Error Code CAA5004B or 80070520

Fix Microsoft Teams Login Error Code CAA5004B or 80070520



When using Microsoft Teams, you cannot help sometimes but experience problems when signing in to your account. Many users complain that they encounter issues each time they try to log in to their Microsoft Teams account on a Windows 10/11 PC or other devices. They may see the error code CAA5004B or 80070520 on their computer screens when launching the app.

Both the Microsoft Teams error code CAA5004B or 80070520 points to problems when logging in. There can be varying reasons why you see the issue. Sometimes, it is due to the Microsoft Teams server. In other cases, you have corrupted cache files. Other times, it is due to your network connection.


How to Fix Microsoft Teams Error Code CAA5004B or 80070520 when Signing In to an Account

Fortunately, there are ways for you to troubleshoot and fix the Microsoft Teams login errors CAA5004B and 80070520 on your Windows computer. Try to follow each of the solutions below one at a time and check if it fixes the error or not.

Method #1 – Perform a Power Cycle on your Device

  • Exit Microsoft Teams and power off your device.
  • Unplug your router and modem.
  • Wait for at least 3 minutes.
  • Now, plug them both back in and connect to the Internet.
  • Power on your device and relaunch Microsoft Teams.

Method #2 – Temporarily Disable your Firewall, VPN, or Microsoft Defender

  • To turn off Microsoft Defender, click the Start button on your Windows PC.
  • Go to Settings.
  • Select Privacy & Security.
  • Click Windows Security.
  • Choose Virus & threat protection.
  • Select Manage settings.
  • Go to Real-time protection.
  • Set it to Off.

If you are using a VPN or proxy server, turn it off and retry signing in to your Microsoft Teams account. You can also try to use any of these premium providers popularly known to work seamlessly with services like MS Teams.

Method #3 – Clear the Microsoft Teams App Cache on your PC

  • If you are using a Windows 10/11 PC, navigate to this path: C:\Users\UserName\AppData\Roaming\Microsoft\Teams.
  • Select all the files and folders and delete them.
  • Relaunch Microsoft Teams.
  • If you are using an Android device, go to the Settings menu.
  • Select Apps.
  • Choose Microsoft Teams.
  • Select Storage.
  • Tap Clear Cache.

Method #4 – Update your Microsoft Teams App

  • On your Android device, head over to Google Play Store.
  • Look for Microsoft Teams.
  • Check if there is an available update.
  • Tap Update.
  • On your Windows PC, launch the Microsoft Teams app.
  • Select your Profile.
  • Go to About.
  • Choose a Version.
  • Click Check for updates.

Method #5 – Sign In using a Different Microsoft Office Product

  • Open another Microsoft Office program like Excel or Word.
  • Click File.
  • Go to Account.
  • Select Sign Out.
  • Now, try signing in using your Microsoft account.
  • Use the same Microsoft account to log in to Microsoft Teams.

Method #6 – Reinstall Microsoft Teams

Lastly, you need to uninstall and reinstall the Microsoft Teams app. Once uninstalled, go to the Microsoft Store, Google Play Store, or the official website of Microsoft Teams. Reinstall the MS Teams app and reboot your device.

Which of the solutions above work for you? Tell us in the comment section below.



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