The issue

The Windows 10 search is not working. No results. Infinite loading.

Solution

Reinstall Cortana (even if you don’t use it at all)

• open powershell (with win+r and type powershell)
• paste this:

Get-AppXPackage -Name Microsoft.Windows.Cortana | Foreach {Add-AppxPackage -DisableDevelopmentMode -Register "$($_.InstallLocation)\AppXManifest.xml"}

It should take couple of seconds.

There are other solutions related to folders permission and registry keys but non of them did help.