RAW digital photography formats typically are not and often cannot be converted between each other, and most likely no program that can achieve mrw to nef conversion exists anyway. RAWs are generally either exported to a digital negative (DGN) or directly to JPEG/TIFF formats for sharing purposes.
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.