Basically I have a duplicate issue of this guy: Super key not working
ALT+F2 opens the "Run a command" shortcut, ALT by itself opens the HUD, but I cannot use any shortcut to open the Dash, which is making Unity very frustrating to use. I can't seem to find a keyboard shortcut setting for it. I can bind other actions to Super and they work as expected, but I don't see any setting to let me use Super to open the Dash...
compizconfig-settings-manager
and under Unity Plugin, "Launcher" tab , check if your Super key is unset. See the screenshot of how it's supposed to look: imgur.com/a/aY8PX If it's disabled , there's the problem