It looks like the DSON Importer didn't import properly. Sometimes Iray materials will break the importer, but it would throw an error.

Sometimes the DSON Importer doesn't generate files correctly. I find that you would need to delete the CR2 created by the DSON importer. It would be in the DSON folder in the Runtime. Unfortunately, the file is buried under subfolders that are unique for each machine.