What is Ks_Shape ?

Hi Experts,

Has anyone had the situation when opening a DWG file that has been created from Prosteel, there are only boxes shown on the display with text saying "Ks_shape (Pro_stahl_3D)" at the bottom of each box. They are denoted as proxy entities and even though the variable for proxy entities is set to on, it makes no difference. 
I have attached DWG file for your reference. Any help will be appreciated.

Thanks

Devaraj.S

 

Crane Support Model.dwg