How can i make the railing follow the curve on these stairs? I have created a path from an edge but i don't know how to align these railing poles to the stairs. I've tried using array and curve modifier but it is all black magic to me and i cannot figure it out how to fix this.

Heres the link to the blend file : http://pasteall.org/blend/index.php?id=52309
To make a non-deformed duplications, you must not use Array and Curve but Duplication, called Instancing in 2.8. 2.8 makes it a bit more complicated than 2.7 in my opinion, but if you don't need to keep a bezier curve you can do it with Instancing > Verts:


Convert your curve to a mesh.





Give it an Instancing > Verts.





Select your pillar, delete the modifiers, parent it to the curve. It should be duplicated along the curve.





You can equalize the gap between the vertices with a W > LoopTools > Space. If you need to move a pillar, just move its corresponding vertex. Also, you can hide the original pillar if needed.