Lauchpad key...

Hi guys,
I was always been using F keys as a MAC keys like keyboard brightness etc, and also Launcpad key.
Then I did go to Settings > Keyboard and there is Launchpad & Dock, and there is Show Launch pad and I accidentally pressed on there, where it shows what command do you use to show it, I pressed F4 which was always been used as a launchpad key and it doesn't open anymore...

edit:



Even that it shows that is F4, it does nothing when I press there. Mission control button works perfectly and opens mission control

 

So there is no solution for this guys?

 

If I press restore to defaults:



But in default, that button worked perfectly. I didn't do anything, it worked straight away from first start.

 

It needs the key then, it doesn't come with any. If I press on F4, it does nothing. It doesn't check as a F4

 

I would'n even go here for a help if that would be good for me. I want it get back to place, not add Fn to toggle everything...

 

And that is what I'm saying, I tried it. Check the box, then go there Fn + F4, keeping it checked, unchecking... I tried everything... Nothing works