All I know is my Samsung S4 with kitkat formatted the drive extfat. I since have removed kit kat put on lollipop and formatted the sdcard fat32. I have had no issues. So if your device is using a different format I don't know. I would recommend putting the card straight into your windows machine then go to disk management this should tell you if its a fat or extfat if it by chance is a ext2,3 or 4 then you will need a third party partition app like Gparted. You will know of its one of the others as windows will probably not recognize the format
You mean exFAT? That's really odd, because exFAT is a microsoft filesystem. This needs a lot more digging on my part. Thank you.
I'm not at all sure where most of the bodies are buried in this thing. Apparently within 4.4, if an application established it's own "app specific directories" (using
getExternalFilesDir()) then it doesn't need the permission otherwise now required if your app was using
getExternalStoragePublicDirectory().
So the information implying that EXT is a requirement seems false. I think.
But it's still the case that we have a number of things going on, and I'm highly suspicous that it's all related to the above change with KitKat:
1. Access to sdcard from within apps that were previously using the sdcard no longer work. Minecraft and several others fell right into this category. They were instantly crocked (for many of us). This was solved by uninstalling and reinstalling (I think).
2. The sdcard for many folks suddenly goes into a very fast mount/unmount/mount/unmount repeating cycle.
3. The sdcard often times becomes crocked completely at the hardware level. Having written unix device drivers in the distant past, I still can't figure out how this is possible, even from the driver level, unless the mount/unmount endless cycle killed it outright with a large number of writes.
4. Formatting the card from the phone sometimes produced these results for folks: a) It didn't do anything, and all the previous files remained, or b) It seems to remove *some* files (presumably the ones that were put their prior to KitKat or from outside the phone), but most come back.
5. Moving an app to SD card (using the phone's options) sometimes makes data used by that app vanish.