"You'll need a new app to open this windowsdefender link" fix

Hi this post is to help people with windows 10 and 11 windows security not working

On windows 11 do this

1. launch powershell as an admin
2. Set-ExecutionPolicy Unrestricted
3. Get-AppXPackage -AllUsers | Foreach {Add-AppxPackage -DisableDevelopmentMode -Register "$($_.InstallLocation)\AppXManifest.xml"}
4. Set-ExecutionPolicy restricted

IGNORE THE ERRORS

on windows 10 do this

1. launch powershell as an admin}
2. run get-AppxPackage Microsoft.SecHealthUI -AllUsers | Reset-AppxPackage
3. if it doesn't work do this
   4) run Add-AppxPackage -Register -DisableDevelopmentMode "C:\Windows\SystemApps\Microsoft.Windows.SecHealthUI_cw5n1h2txyewy\AppXManifest.xml"
4. run get-AppxPackage Microsoft.SecHealthUI -AllUsers | Reset-AppxPackage

Does the Windows 11 PowerShell command ignore the errors or actually resolve the issue? I'm running Windows 11 and seem to be missing the C:\Windows\SystemApps\Microsoft.Windows.SecHealthUI_cw5n1h2txyewy\AppXManifest.xml folder / file that I believe Windows Security relies on. So would this restore that folder / file?

it works !

Very Good

Thank You so much! It worked. ^_^

I was facing the same exact issue.It was working for Admin account but I was unable to launch it for secondary (Standard User) accounts. The solution described in OP did not work for me. I removed secondary account and then added it back and it worked for me.