Although both .drwprp and .sldmat files originate from SolidWorks, conversion between these two file types seems unlikely. If you are looking for anything specifics or know anything useful about how to potentially convert drwprp to sldmat, please write it in the discussion or on our forums.
This conversion entry was verified by us and conversion was flagged as wrong or not possible.
Usually this happens when the conversion would try to convert different types of data between each other, such as audio to image, or it is not possible because incompatibility between programs, caused by closed file formats, very limited support etc.
If you find entry that you feel is flagged as bad wrongly, please tell us in the discussion below with as much as information as possible so we can fix it.