This Microsoft Teams error most likely occurs due to a bad update or a corrupted Microsoft Teams cache. On Windows 11, you can also face this issue due to corruption affecting the UWP installation of MS Teams. If the affected PC is connected to a shared network, you should also investigate for a corrupted MS Teams credential inside Credential Manager. Use the potential fixes below to troubleshoot the issue. 

1. Install the WU hotfix

The biggest surge of this Microsoft Teams 80080300 error started when Microsoft pushed the updates KB4560960 and KB4534132 on the retail and insider preview channels on Windows 10.  Since then, Microsoft has rectified the issue via a couple of hotfixes deployed on every currently supported Windows version (Windows 10 and 11).  Unfortunately, Microsoft is consistently releasing bad updates that mess up the functionality of UWP (Universal Windows Platform) apps, including Microsoft Teams. If you’re experiencing this issue due to a new bad update or have just installed updates KB4560960 or KB4534132, follow the instructions below to install the hotfix released by Microsoft. If the problem is still not fixed and you started to experience this issue after installing a new Windows update, chances are Microsoft didn’t release a hotfix yet. In this case, move down to the next method below, where we attempt to uninstall the problematic update (if there is one

2. Uninstall the latest Windows update

If the issue is tied to a bad Windows Update and there’s no hotfix available, you should first uninstall the problematic update. You can do this by accessing the Programs and Features screen and triggering the uninstallation from the View installed updates tab. But our recommendation is to do it directly from the recovery menu – this will allow you to revert feature updates and cumulative updates and delay their installation until Microsoft finally arrives with a hotfix.  Note: It’s important to remember that a bad update might not be the only cause of this problem. In this case, following this procedure will not harm your PC. Deleting the latest update will prompt your operating system to reinstall it correctly after a few days. Follow the instructions below to uninstall the latest update from the Recovery menu: Note: The instructions below will show you how to ‘brute-force’ your way into the Recovery menu without using a compatible installation media.  If you’re still experiencing the 80080300 error, move to the next method below.  If this method was not applicable or you already uninstalled the latest update with no effect, move down to the next method below. 

3. Run Teams in compatibility mode (Windows 10 Only)

If you are experiencing this issue on Windows 11, there’s a chance you will be able to fix the issue by forcing the Microsoft Teams UWP app into compatibility mode with Windows 8.1. There’s no official explanation from Microsoft on why this method eliminates the 80080300 Teams error, but affected users put the blame on a bad UWP version that is maintained by the Microsoft Store component. To fix this issue, you need to access the Properties screen of Microsoft Teams and force it to run in compatibility mode with Windows 8.  Important: If you’re on Windows 11, you will not be able to use this fix since Microsoft Teams comes pre-installed as a UWP app in an inaccessible location. Follow the instructions below for specific steps on how to do this on Windows 10: If the problem is still not fixed, move to the next method below. 

4. Delete the Microsoft Teams cache folder

If running Microsoft Teams in compatibility mode with Windows 8 was not an option, one easy fix you can implement on Windows 11 is clearing the cache folder. This fix is confirmed to work on both Windows 10 and Windows 11. You can enforce it from the Apps panel by resetting the app from the Advanced options.  Here’s how: If you still see the 80080300 after the login fails, move down to the next method. 

5. Reinstall Microsoft Teams

If none of the potential fixes below have worked for you, it’s time to start troubleshooting for a potential issue caused by system file corruption. Although cases are rare, it has been confirmed that reinstalling the application before downloading & installing the latest version from the official Microsoft update is effective in fixing the 80080300. Note: This method is confirmed to work on both Windows 10 and Windows 11. The instructions below should work on both versions.  Follow the steps below to uninstall your current Microsoft Teams version and install the latest version from the official channels: If you still see the 80080300 error, try the next potential fix below. 

6. Remove Saved MS Teams Credentials

In case you’ve troubleshot using every method above, and you’re still seeing the 80080300 error every time you attempt to log in, start looking into Credentials Manager. Newer versions of Microsoft Teams are known to sometimes corrupt saved credentials if the same Teams account is used across multiple devices connected to the same network. If this scenario is applicable, you can fix this issue by going into Credentials Manager and deleting every saved Microsoft Teams credential on this device.  Note: If you are experiencing this issue with a shared network, you should repeat this process on every PC throwing the 80080300 error. Here’s what you need to do:

Microsoft Teams Users: 3×3 Grid View Is Nice, But A 5×5 View Is What We Need For…How to Fix Can’t Sign into Microsoft Teams Error Code CAA2000B on Windows 10?How to Fix “Error code caa7000a” on Microsoft Teams?How to Fix “Error Code: 0xc0000020” on Microsoft Teams? How to Fix Error Code 80080300 in Microsoft Teams  - 56How to Fix Error Code 80080300 in Microsoft Teams  - 2How to Fix Error Code 80080300 in Microsoft Teams  - 92How to Fix Error Code 80080300 in Microsoft Teams  - 42How to Fix Error Code 80080300 in Microsoft Teams  - 89How to Fix Error Code 80080300 in Microsoft Teams  - 49How to Fix Error Code 80080300 in Microsoft Teams  - 26How to Fix Error Code 80080300 in Microsoft Teams  - 1How to Fix Error Code 80080300 in Microsoft Teams  - 23How to Fix Error Code 80080300 in Microsoft Teams  - 77How to Fix Error Code 80080300 in Microsoft Teams  - 45How to Fix Error Code 80080300 in Microsoft Teams  - 83How to Fix Error Code 80080300 in Microsoft Teams  - 85How to Fix Error Code 80080300 in Microsoft Teams  - 45