I had the same problem 3 days ago.
Below is what i did.
1. Download the firmware, unzip and save to any folder in your computer.
2. Remove your micro sd card from the player.
3. Backup your music folder in the player to your computer (very important as you will copy your music file back to your player).
4. In the folder of your firware, there is a program, StUpdaterApp_4MIN.exe, doubl click to activate the program.
5. Connect your player to the usb port of your computer and press the middle butten of your player, once you see the RoCoo and quickly press the upper butten (this will activate the player's usb port.
6. Then go to your program that you activated before, you will see the program will detect your player.
7. Choose format the memory of the player and press start.
It works for me.
I hope the above helps.