It worked under mac... I didn't realize that I had to copy the directories  and  into the root directory as well as the file [metainfo2.txt] into the root. When I did that and shoved it into the slot it worked perfect. It took almost an hour to complete the firmware update.You have to do it on a Windows PC or a Mac running Windows bootcamp. I did the latter.
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to be clear... it did work on mac. I had an old FAT formatted 32GB SD card which i stuck in the SD slot on my mac. copied the zip file onto it. hit extract. and then pulled the extracted files into root rather than [rns850_k0711].
now try the maps.