"File Explorer" button in Start menu is not working

My "File Explorer" button in Start menu is not working. When I press on it nothing happens.
Already tried: SFC/scannow, reboot, restart explorer.exe

Can you launch explorer
a. with Windows key + E?
and
b. with Windows key + R, then type explorer.exe in the Run box?

IF you can open an instance of explorer, go here:
C:\Users\David\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\System Tools
You could try copying an explorer shortcut into that from here (or similar folder - yours may not have quite the same title)
C:\Windows\WinSxS\amd64_microsoft-windows-explorer-shortcuts_31bf3856ad364e35_10.0.10586.0_none_443d824ebb4341e2

Thanks for your help. Ends up it was a registry modification i did to get rid of "Quick access" in file explorer, so i reverted that and now it works fine.