Ok, so If you try WorldEdit itself, it doesn’t work properly you will need WorldGuard to do that.
So that is why i’m requesting WorldGuard, Because you get to add Protected Areas where people cannot destroy, Disable Fall Damage in that area “Great for Droppers where you want the person to fall on the Lime Block and Survive, even from a Fall Height! And disable people from Breaking Blocks No more “Haha I will break this guy’s blocks when he leaves” It will be Protected by WorldGuard!
I know you can add it 
. If not, How are worlds gonna be Protected?
A Forge Software Mod.
Download here:
