I was able to resolve this for a user without deleting the user.
I had this issue on a Lenovo.
wsappx was causing high CPU, fully occupying a single core. Upon logon the user had a black screen post KB4093112 update and to make matters worse the start menu and some other buttons were no longer working if the black screen finally dissapeared.
I had two user accounts on the laptop. A local account that was not affected and a domain account that got affected by this issue.
I did the following operations on the local account that was not affected. If you only have one account. Use task manager and start cmd as administrator to make a new user account to do these operations.
With the non impacted account, launch powershell as administrator and run:
Get-AppxPackage -User <impactedusername> | Remove-AppxPackage
This will spawn some errors but keeps processing. Once done open explorer and navigate to c:\users<impactedusername>\appdata\local\
Rename the directory "Packages" to Packages.backup
Now reboot the computer and login as the impacted user. Windows will recreate basic AppxPackages that we removed and create a fresh start menu. wsappx will no longer be crashing and will be updating packages properly now. If needed, you can reinstall
build in apps
https://www.cnet.com/how-to/how-to-reinstall-default-apps-in-windows-10/
I can confirm this works.
I actually went another route, but very similar
(Get-AppXProvisionPackage -Online).PackageName | Out-File -Path C:\Temp\AppLists.txt
Opened the Appslist.txt created and removed the Apps from the list that I wanted to keep, Store, Calculator, DesktopAppInstaller.
Then back in powershell
$apps = get-content C:\Temp\AppLists.txt
$apps | Foreach {Remove-AppXProvisionPackage -Online -PackageName "$_"}
This stops these apps from being provisioned for new users, as it was any new users to the computer having the problem.
Doesn't work for current users would have to use David's command or remove their profile and re-add it.