Go to Go to Computer Configuration > Administrative Templates > Windows Components > App package Deployment to check settings for these policies:.This opens the Local Group Policy Editor screen.In Windows, search for Edit Group Policy or right-click the Windows Key and select Run > type 'gpedit.msc'.Allow all trusted apps to install (disabled).Prevent non-admins users from installing packaged Windows apps.Some of the known GPO policies that could be preventing installation include: There are a few policies that could alter these registry keys and block app installation in your organization due to restricted policy set by the admins. Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Appx.Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\AppModelUnlock.These registry keys can be found at one of these locations: If this optional October update isn't available for your OS build, the November security update will include the fix. This issue has been fixed in the Windows October cumulative update KB5031455. If AllowAllTrustedApps is disabled, the new Teams app (MSIX) installation fails.