Pro_Stahl_​3d Object Enabler for AutoCAD 2015

I have received a DWG from a project, that contains 3D objects that I would like to use. When I open the files in AutoCAD 2015, it asks for a Missing Application: Pro_Stahl_3d.

From Google and AUGI searches I think that Pro_Stahl_3d is Bentley Pro Steel, but I have no confirmation of that.

If the application Pro_Stahl_3d is a Bentley application, does Bentley make an object enabler for these objects to be visible in AutoCAD 2015?  If yes where can I download it?