Microsoft Teams have a bundle of excellent and attractive features that provides you with easy communication among friends, even classes and offices were conducted online. There’s a lot going on in MS Teams, for example, you can chat via messages and video calls, and at the same time share files and folders. However, some of its users are agitated as they are not able to sign in, and instead, they face CAA20004 Microsoft Teams Sign-in Error. In this tutorial, we are going to see what is causing the error and learn what to do in such cases.

Something went wrong
We couldn’t sign you in. If the error persists, contact your system administrator and provide the error code 0xCAA20004

Fix CAA20004 Microsoft Teams Sign-in Error

Microsoft might stop you from signing in if have if you are entering the wrong username and/or password, if your Internet is slow or if there is some issue with the server. These reasons are very common and before troubleshooting or even probing the error further, you should check if you are not encountering these issues. However, the CAA2004 mostly occurs when AD FC Endpoint is disabled. But this doesn’t mean that it is the only reason. In this post, we will give every possible solution to resolve the error in question. So, if you encounter CAA20004 Microsoft Teams Sign-in Error, execute the solutions mentioned below to fix the error in question:

1. Update Microsoft Teams
2. Enable ADFS endpoint
3. Run the Windows Store App troubleshooter
4. Clear Teams cache
5. Repair or Reset MS Teams
6. Reinstall Teams

Let’s get started with these solutions.

1] Update Microsoft Teams

Before coming to any sort of conclusion, you need to first check whether the MS Teams version you are running is the latest one or not. To check this you can click on three vertical dots> Settings > About > Version. If it is not the latest one, select Check for updates. This will check and install the update if available. Once it is updated, sign in to check if the issue is resolved.

2] Enable AD FS Endpoint

Microsoft Teams Sign-in Error is a backend error that happens due to Microsoft Teams Server not being able to authenticate the account. Microsoft Product like Office and its other servers works on the Azure platform and this cloud platform support WS-Trust Kerberos authentication and endpoints of ADFS. So, if WS-Trust Keberos is unable to authenticate the login then you are definitely going to see the error code CAA20004 and similar errors.

If you want to avoid this situation then you can enable the AD FS endpoint. However, do keep in mind that you can do this step only if you are running the system which has access to the server that contains all user accounts active directories. Here’s how to do the same:

• Open the AD FS Management app on the admin’s system.
• Click Edit Global Primary Authentication from the column on the right.
• Now tick the box next to Form authentication in both Extranet and Intranet sections.
• Select the box next to Windows authentication in the Intranet section.
• Now, click on the Apply button.
• Open Powershell with admin rights and execute the following command:
  Enable-AdfsEndpoint -TargetAddressPath
  “/adfs/services/trust/13/windowstransport”

See if the issue persists.

Note: If you are a client user, you don’t have to do all this, just inform your network admin and they will make adjustments.

3] Run the Windows Store app troubleshooter

In case you are using the Teams Microsoft Store app, you can use the Windows Store troubleshooter to resolve the issue. This tool allows you to know the cause behind the error and provide you with a way to correct it. To do the same, follow the steps mentioned below:

Windows 11

1. Click Win+I to open Settings and in System, select Troubleshoot.
2. Now, click on Other Troubleshooters.
3. Find Windows Store App and select the Run option.

Windows 10

1. Right-click on Start and then click Settings.
2. Go to Updates & Security > Troubleshoot.
3. Click on Additional troubleshooters.
4. Select Windows Store App and then click on Run the troubleshooter.

Once the process is done, you will know the culprit causing the issue and then click on Apply this fix to solve the problem.

This will not apply in case you are using the Teams Desktop software.

Read: Fix Microsoft Teams not downloading files

4] Clear Teams cache

There is a high possibility that you are facing the issue due to caches. So, in such scenarios, you must clear the Teams cache to resolve the issue. If you are using a browser, then you may want to clear the cache of that browser. To clear the cache of the MS Teams app, open Run and paste the location: %appdata%/Microsoft/Teams, and now, select all the content of the folder and delete them. After that, restart your computer, launch the application and check if the issue persists.

5] Repair or Reset MS Teams

A lot of users reported that repairing and resetting the app seems to do the job. Therefore, we are going to do the same and then try to sign in. To Repair or Reset Microsoft Team in Windows 11/10, follow the given steps.

1. Open Settings and go to Apps > Apps & Features or Installed apps.
2. Search Microsoft Teams and click on the three vertical dots.
3. Now, click on the Advanced Option.
4. Select Repair or Reset from the next panel.

Launch MS Teams and sign in. Hopefully, this will do the job.

6] Reinstall Teams

If none of the above-mentioned solutions work for you, you have to reinstall MS Teams. If you are worried about your data, then it is not the topic you should be worried about as your data will already be synced, you are not going to lose anything. Follow the steps prescribed below to uninstall Microsoft Team in Windows 11/10.

1. Open Settings
2. Click on Apps > Apps & Features or Installed apps.
3. Look for Microsoft Teams.
   • For Windows 11: Click on the three vertical dots and click Uninstall.
   • For Windows 10: Select Microsoft Teams and click Uninstall.

Now, download a fresh copy of Microsft Teams and install it on your computer.

Read: Fix Microsoft Teams Login issues: We couldn’t sign you in.