Unable to swipe between full-screens or view multiple desktops

I was searching for an answer to this, and saw no clear answer.

(I had the same problem.)

It is likely that multiple full-screens (desktops) had not been set up.

To set up more screens (desktops).

Go to mission control by tapping F3, with the box icons on it.

This gives a view of all your open apps.

On the top right, there is a plus sign.

This will add extra full-screens (desktops).

Now you will be able to scroll left and right, with three (or four) fingers.

RE