Resolve an import AutoCad - 3D Max problem

[stefan.serban.l]

Hello, I have a problem with something in 3D Max and i can't find a solution googling it. I imported a file with several layers from AutoCAD to 3D Max. A layer have many objects but they allways work as a group, for exemple if i select a chair, it selects all chairs (from the layer chairs). I want to put diferent materials for each one, but they work as a block. I'v tried to ungroup them some how but it dosen;t allow me

[PROH]

Hi. Look at my answer in your previous identical post.