I've started using the keyboard shortcuts in Linux Mint with the Gnome desktop, and I've found that they don't work unless I first click on the desktop with the mouse.

The problem occurs if I start with no application windows open, then open a single application, and later close it leaving an empty desktop. If any other app windows are open the keyboard shortcuts still work. But if there are no other windows open the shortcuts fail to work until I click on the desktop. It's as though the system fails to return the input focus to the desktop when the last remaining app window is closed.

Is it supposed to be like that?

Changing the workspace does the trick for me. Just try switching the workspace by using Ctrl + Alt + Right Arrow shortcut keys work fine now...

Thanks, I'll do that from now on.

For some reason, the problem has disappeared since I booted up today. <shrug>