There is data but Pen drive shows empty
It's Normal issue, people daily face it
To solve it out
Click on "Start" ==>Run ==> Type cmd and press Enter.
Here we suppose that pendrive drive letter as H:
Enter this command.
attrib -h -r -s /s /d h:\*.* ==> Press Enter
You may copy above command and then paste it in command prompt
Must not forget : Replace the letter h with your pen drive letter.