If u r using windows - Make it FAT32 or FAT16. Others dont work.
If you format a card with Windows it will not comply with the SD standard. That's the point of this post.
I repeat, use SD Formatter and avoid potential problems that can be caused by the Windows formatter.
Found from Arduino SD Lib
Much of the write-up for the SD library is wrong. I wrote the old version of SdFat that is used in SD.h. Too bad the Arduino company has not fixed bugs in the code or the write-up for years.