Stairs by sketch

[Anonymous]

Hi everyone hope someone can help

I'm having problems trying to create a stair by sketch.

I'm following this tutorial below, but when i go to complete by stair i get the error message 

"stairs require no less than two boundaries (chains of one or more boundary lines)."

https://www.youtube.com/watch?v=he4NLtBo5GQ

No matter what i do doesn't seem to alter....any help greatfully recieved, i'm a newby

[Anonymous]

Hello! It would be better if you will attache the file with stair that you are trying to make. And we will found out where you have the problem.

[RDAOU]

@Anonymous

Do not close the boundary lines (the green ones).

You should have at least 2 meaning...There should be at least 2 green boundary (consisting of 1 or more continuos lines each)... 1 green boundary at the left and 1 green boundary at the right (they should not be closed or connected at either ends)