Cant make a simple door

I know how this sounds but ive tried everything and I cant get a doorway to appear.
I tried it with the new project floor and cloned them into a room with a bsp cube sub
and nothing. Then I tried to make a room full of dsp cubes additive and then mad a dsp cube
sub and all I get is this indentation in the wall. If your confused this is what im trying todo

https://www.youtube.com/watch?v=6etfz1dwiYc

Im using the most recent UE4. 4.8.2

Any help would be appreciative

Nvm I found it lol