I have the same problem, windows support told me to reset microsoft store and it's gone. I tried this command and got the same error message.
: Deployment failed with HRESULT: 0x80073CF6, Package could not be registered.
error 0x80040154: While processing the request, the system failed to register the windows.capability extension due to
the following error: Class not registered
.
NOTE: For additional information, look for [ActivityId] 256c3bf6-e210-0002-e076-6c2510e2d601 in the Event Log or use
the command line Get-AppPackageLog -ActivityID 256c3bf6-e210-0002-e076-6c2510e2d601
At line:1 char:53
- ... | Foreach {Add-AppxPackage -DisableDevelopmentMode -Register "$($_.I ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : WriteError: (C:\Program File...ppXManifest.xml:String) [Add-AppxPackage], IOException
+ FullyQualifiedErrorId : DeploymentError,Microsoft.Windows.Appx.PackageManager.Commands.AddAppxPackageCommand