For those of you still struggling with this:
Option 1)
Go to show (level editor toolbar)>advanced>CHECK grass.
*Note: this settings is unique to both game-view and editor-view, so it needs to be enabled for both (as one case was that the grass was not displaying in game view, but was fine in editor view).
*These view options are stored in the editor config and persist between editor re-loads.
Option 2)
Show (level editor toolbar)>Use defaults. This will set everything back to normal, which includes setting grass visible on game view and editor view.
