Apple - Can't format samsung 128 evo micro sd card

In the half-dozen or so instances where I've seen this specific error, the micro SD card itself had gone bad and couldn't be formatted on Mac, Windows or Android (via OTG), even with different card readers. Not only couldn't the card be formatted, but files couldn't be added or deleted nor anything else that required writing to the card. (Reading files was unaffected.) It was effectively in read-only mode like a full-size SD card with the switch flipped, but obviously the micro SD doesn't have that. Only solution is replacement.

I know this is an old post, but I thought I'd add the real cause (i.e. a defective card, not a software or format issue) for future reference.


FAT32 cannot format partitions bigger than 32GB. You will have to use a different partition scheme that is compatible with whatever device this SD card will go into, like exFAT.