Bad stairs rendering in 3D view

[Moose24]

Hello ! 
I added a quite simple stair to my project and the 3D rendering (in AC26 or AC27)  is bad on the interior angle.

I've tried to change stair parameters but nothing helps.

Have you any idea or solution to my problem ? 
Thanks in advance

[Barry Kelly · Accepted solution]

The internal corner is probably too tight to have a stringer.

Horizontal distance is too short and vertical distance is too high and the corner angle too great for it to work.

You would probably be best with a newel post in that corner.

Barry.

[Moose24]

Thanks Barry,

You were right, the corner part was too short.
I used the split function in edit mode to delete the lower stringer and added a pole (and a railing).
My stair is now very realist and looks (almost) like the real one.
Best regards