Please repair and reset the Settings app using the following commands.
From PowerShell (admin), run:
Get-AppXPackage windows.immersivecontrolpanel -AllUsers | Foreach {Add-AppxPackage -DisableDevelopmentMode -Register "$($_.InstallLocation)\AppXManifest.xml" -Verbose}
Get-AppxPackage windows.immersivecontrolpanel | Reset-AppxPackage
(If you get any errors, please post the output here.)
If the commands run correctly, restart Windows and see if you can open Settings.