Corona version 9
The model uses materials that may not be displayed correctly in very old versions of the engine.

Reiki ladder from Sofia (three-dimensional effect)
Due to its design it is possible to finish both round columns and radius walls
https://sofiadoors.com/blog/reiki-lesenka/ 

A number of elements are left in the scene with the possibility of changing bends through Path Deform
All elements are duplicated in non-editable Editaible Poly

Dimensions of objects:
1 element size 104 *42 mm length 3000 mm
Columns with diameters of 600 800 1000 mm
Straight panel with rounding 700 mm radius
Arbitrary curved panel 10 m long

Objects are logically adjusted pivots are configured textures and materials have logical names
Texturing UnwrapUVW
Vray materials are obtained by conversion

For Corona render it is recommended to install a version not lower than 1.5 since the glossiness of materials is configured with PBR in mind

Who works in a V-Ray version lower than 3.1 be careful in the materials in the BRDF section there is a Microfaset GTR ( GGX) if your version is older than 3.1 then the BRDF field will be empty. Choose Blinn Phong or Ward – which is preferable for you