[sc00b4s7eve]

I suggest finding a free trial or even a "free trial" of Pocket Mechanic because it will scan your memory card for bad sectors and mark them so you can use the rest of the card again.

Alternately, you can try and use the card reader in a Mac or Apple computer just to see if it's a card error or a file system error.

Btw: I would only accept the prompts to format that card as an absolute last resort seeing as though you will use all your data.