I'm trying to create a monolithic concrete stairs following this tutorial http://usa.autodesk.com/adsk/servlet...112&id=3027322 however i'm not sure if it is just me or there is really a little bit of a problem with the tutorial. If you follow exactly the tutorial the upper end of the stairs will leave a gap from the upper level boundary of the stairs. If you set the Riser Type back to straight or incline instead of none it will also give you a very thin riser at the top most part. Any idea guys?

BTW, my requirement is actually a U shaped monolithic concrete stairs. I did try creating one following the above tutorial but it gives me an error message "A piece of boundary is too short to create a boundary on it".

I'm confused which part it is referring to.