SD card is damaged, in addition to this format, can also solve it with another method

1. Unplug the phone's SD card, insert the card reader, showing the removable disk on your computer.

2. Open the Start - Run –CMD

3 run CMD in "chkdsk / f *:" (* is your removable disk (SD card) letter)

4 Click the Enter key, to start repair...

5. After the repair, right SD card properties - tools - start checking - the "Automatically fix file system errors" and scan and attempt recovery of bad sectors "Both are marked with" √

"6 can be inserted back into the phone.