That's a good one and they all should be down there
On my last trip to Brazil's Pantanal with my new Mac Book Pro I had the same problem. One of my guests figured it out as my Western Digital hard drives were all formatted in NTFS but once we reformatted them to exFat there was not problem backing up my photos.
I purchased one last fall and so far I like it. Still learning how to use it since it is my first Mac
Heard this one before but it still good
Now the real work begins hate this part as it takes so long