Thank you Lars, about the file extensions, I just asked because they are named now as Bryce 5 mats..oh well...THAT doesn't seem to be the problem then... For the black materials...I didn't changed the folders and everything is still there...I've get even the names of the materials in the editor. It's only these two categories (glasses and metals) where nothing comes up and no materials get transferred to the object. (I deleted any .prv files but it didn't help) Is there anything else I could try? Thank you!