No paint foliage in landscape

Hi, I’ve been creating a level, when it comes to adding grass does not let me for some reason, what happens? This is the screenshot thanks.

you looked if the foliage check is checked at the foliage type?

might be the density of grass, i see 4 or 5 grass chunk in the ground

If you are using level streaming then the paint tool will only work and add foliage on surfaces that are part of the selected level.