How to get rid of those triangles in this scene

Hi everybody,please i have a problem.i just downloaded a scene and when i opened it,some objects were replaced by triangles clouds i want to know if it’s an error and if i can get the original objects back in the scene with their real topology and textures.Here is an image to show you what i’m saying

These might be vray proxies. It is a vray function that change complex components into light version of them. Once you launch a vray render, the items will show and be rendered just fine.
When you make a proxy of an item, it gets externalised from your SketchUp model, being saved in a mesh file. If you don’t have this file, you won’t be able to render it.