After the latest update of Windows 10 preview all the “Modern Apps “where not working anymore.

You can re-register all apps bij entereing the following command in an Admin Powershell prompt
Get-AppXPackage | Foreach {Add-AppxPackage -DisableDevelopmentMode -Register “$($_.InstallLocation)\AppXManifest.xml”}

If still not working you can try this procedure :

  1. Run regedit 
  2. Check if system is the owner of the key  : (right click over the key Packages and select Permissions. Now in the following window, click Advanced)
    HKEY_CURRENT_USER\Software\Classes\Local Settings\Software\Microsoft\Windows\CurrentVersion\AppModel\Repository\Packages
  3. run Powershell with admin rights and enter this code :
    Powershell -ExecutionPolicy Unrestricted Add-AppxPackage -DisableDevelopmentMode -Register $Env:SystemRoot\WinStore\AppxManifest.xml
  4. If  none of the Modern apps are working , then paste this also in the open PowerShell box:
    ((Get-ChildItem “HKLM:SOFTWARE\Microsoft\Windows\CurrentVersion\Appx\AppxAllUserStore\InboxApplications”) | Get-ItemProperty).Path | Add-AppxPackage -Register -DisableDevelopmentMode
  5. If you also encounter issues with apps from 3rd party suppliers a registry key needs to be deleted :
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Appx\AppxAllUserStore\[UserSID]If you don’t know your user ID fou can find this by entering the following command “executing wmic useraccount get name,sid” in the command prompt.
  6. Restart your system and all the apps should be working fine.