How to Fix Can’t Sign into Microsoft Teams Error Code CAA2000B on Windows 10?

Microsoft Teams is a reliable product offered by Microsoft like its other services but recently Teams login error such as error CAA2000B is being reported by many users on numerous online support forums. The problem arises when a user tries to log in to his/her account. The error is extremely frustrating as it prevents users from using MS Teams which ultimately stops their education/business work. This creates an unfavorable experience for end-users as it directly affects their work. The error notification is as follows:

What Causes Can’t Sign into Microsoft Teams Error Code CAA2000B?

We have listed down some of the causes of this problem after reviewing the user’s feedback and technical authorities in detail. This problem may arise due to any of the following reasons:

Note: Before attempting any solution, quit the Microsoft Teams application from Task Manager to ensure you won’t lose any data. Furthermore, please sign into MS Teams using Web Browser to see if you can sign in there. In case you can, this error is strictly because of your Microsoft Teams desktop application.

Solution 1: Reset Internet Settings

As discussed in causes, bad internet connection or faulty internet settings may cause this problem. Users were able to resolve this issue after they had reset Network Settings. Follow the steps given below:

1. Click Start, search Internet Options, and open it. This will open a window that contains internet related settings i.e. General, Security, Privacy, etc.

   

2. Switch to the Advanced tab and click Reset. Windows will now initialize resetting all internet options, discarding all the settings that were made to them.

   

3. Now launch Microsoft Teams and try to log in. This should fix your problem.

Solution 2: Clear Microsoft Teams Cache

As discussed in causes, corrupted cache data blocks authentication certificates which ultimately cause the error under consideration. Many users have reported that resetting/clearing MS Teams cache data helped them in resolving this problem. In this solution, methods for both Windows 10 and macOS have been provided. Kindly follow the steps followed by your operating system to fix this error.

For Windows 10 users:

1. Right-click on the taskbar and select Task Manager from the list.

   

2. Look for Microsoft Teams in the Processes section, right-click and select End Task. This will terminate all the background ongoing processes related to MS Teams.

   

3. Click Start, search File Explorer and open it.

   

4. Copy-paste the following location address in the address bar and press Enter. This will take you to a hidden folder named cache that contains cache files for MS Teams.

   %appdata%\Microsoft\teams\Cache

   

5. Select all files by pressing Ctrl + A keys together on your keyboard and permanently delete all files in the folder by pressing Shift + Del keys together on your keyboard. Select Yes to confirm the deletion process.

   

6. Now repeat the steps from 3 to 6 one by one for the following location addresses:

   %appdata%\Microsoft\teams\application cache\cache
   %appdata%\Microsoft\teams\blob_storage
   %appdata%\Microsoft\teams\databases.
   %appdata%\Microsoft\teams\GPUcache
   %appdata%\Microsoft\teams\IndexedDB
   %appdata%\Microsoft\teams\Local Storage
   %appdata%\Microsoft\teams\tmp

7. Once you have deleted all files, try running Microsoft Teams and then logging in. This should fix your problem. In case it does not then proceed with the final solution.

For macOS users:

1. Quit Microsoft Teams and copy-paste the following location address in spotlight search and press return. This will take you to a hidden folder named cache that contains cache files for MS Teams.

   ~/Library/Application Support/Microsoft/Teams/Cache

2. Select all files by pressing command + A keys together on your keyboard and permanently delete all files in the folder by pressing option + command + delete keys together on your keyboard.
3. Now repeat the steps from 3 to 6 one by one for the following location addresses:

   ~/Library/Application Support/Microsoft/Teams/Application Cache/Cache
   ~/Library/Application Support/Microsoft/Teams/blob_storage
   ~/Library/Application Support/Microsoft/Teams/databases
   ~/Library/Application Support/Microsoft/Teams/GPUCache
   ~/Library/Application Support/Microsoft/Teams/IndexedDB
   ~/Library/Application Support/Microsoft/Teams/Local Storage
   ~/Library/Application Support/Microsoft/Teams/tmp

4. Select the Finder application, click Utilities on the Go menu, and then double-click Keychain Access.
5. Find Microsoft Teams Identities Cache and delete it.
6. Once done, try running Microsoft Teams and then logging in. This should fix your problem. In case it does not then proceed with the final solution.

Solution 3: Clean Uninstall & Reinstall MS Teams

If clearing the Microsoft Teams cache didn’t fix your problem then there is a strong possibility that some of the Microsoft Teams system files are corrupted. The easy fix would be to completely uninstall MS Teams and reinstall the latest fresh copy. This proved to be a helpful solution for many users online. Follow the steps given below to do so:

1. Close MS Teams by right-clicking the MS Teams icon in the taskbar and select Quit. This will end all the background ongoing processes related to MS Teams.
2. Right-click on Start and select Control Panel to open it.
   

   

3. Select Uninstall a program under the Programs section. This will take you to the list of all installed programs on your PC.
   

   

4. Select Microsoft Teams from the list of installed programs and click Uninstall. This will start uninstalling MS Teams. The procedure may take time so wait until it gets finished.
   

   

5. Press Windows + R keys on your keyboard to open Run dialog box.  Type %appdata% and click OK. This will take you to a hidden folder named AppData where user data is stored for different applications installed on your PC.
   

   

6. Open Microsoft folder, right-click on Teams folder and select Delete.
   

   

7. Close all windows and again press Windows + R keys on your keyboard to start Run. Type %Programdata% and click OK. This will take you to a hidden folder named ProgramData where program-related settings or data are stored.
   

   

8. Repeat step 6. Now you have finally uninstalled Microsoft Teams completely from your computer.
9. Download a fresh updated copy of Microsoft Teams desktop setup from the Official Microsoft Teams Download Webpage and then install it. This should finally fix your problem.