(1) Update Windows 10 to the latest updates, (2) run sfc /scanow, (3) run an online DISM repair: DISM /Online /Cleanup-Image /RestoreHealth (4) uninstall 3rd party programs that may be interfering with Windows 10, like classic shell -- or try to pinpoint what you may have installed that agitated it
If that doesn't fix it, reinstall. Then as you use Windows 10 keep a track record of what you do that may cause the problem to re-appear.
I hate to say it but Windows 10 is a black box, and sometimes when it breaks there's not a whole lot you can do. 10's start menu and search feature are infamous for not working.