When I make a monolithic concrete stair (ends with tread) with a landing at the top, I simply extend that top tread out to make the landing.
On a steel stair (ends with riser), I tried to make a landing by drawing extra boundary lines at the top of the stair, similar to the boundary lines at a landing when you make the stair turn or return back, but it didn't like me doing that. It gave me an error saying "Stairs require no more than two boundaries (chains of one or more Boundary Lines)." I also tried extending the boundary lines on each side of the stair and joining those with another boundary line but it made the same error.
Is there any way to make a top landing part of a steel stair, or do I have to create a separate floor of the same thickness as the stair treads? I wanted to make it part of the stair so that the stringers would run around the landing. I thought I had done something like this before but I can't figure out what to do. What am I missing here?