Command + H Hide active window option disabled

Not sure what I did, but all of a sudden I can no longer use the Keyboard Shortcut, Command + H to hide windows. When I click on the menu, like Firefox, it shows it in the list, but it's grayed out and it won't let me select it. Somehow I must have accidentally clicked something to disable it.

No matter what program I open, they all have the same grayed out menu option for the Command + H