Unfortunately, DIM only handles zip files available at DAZ3D. Those are properly compressed for DIM use. You are wasting your time trying to force DIM to recognize Renderosity based DS files. Your best bet is to open the compressed files and take a look at how the individual folders are set up. If you see several individual folders, i.e., data, people, etc, then those folders can be decompressed directly into your DAZ Library folder (either My DAZ 3D Library, which DIM prefers or My Library). If you find that the primary folder is called Content, then you will need to enter that folder and transfer the folders within to the aforementioned DAZ Library folders. Renderosity compressed files are not DIM ready as I mentioned before, you will need to manually transfer files into the library. Any files you encounter with a Content folder as a primary folder is incorrect and should never have been constructed that way. There is no Content folder in the DAZ library.