I downloaded lots of online creations but the achievement wasn't popping for me. So to clear up any confusion, I think I understand how this works:
if you look in the top left corner of each created level, you wiill see different icons there. The lightbulbs are Solutions, The Red cogs I have no clue (I rented so I have no manual to check) and then there are levels with a green tree on them. I downloaded one of these with the tree on and the achievement popped. Hope this helps :)