Flash error please back up the data and format disk

Reformat the player.
If you have a Windows-based computer,
Try this: disconnect the player from the computer, turn it off, hold in the volume + button, and reconnect the player to the computer while holding the volume + button in. Keep holding the volume + button for an additional 5-50 seconds. Windows should eventually go into recovery mode and revive the player- it will pop up a window that says Found New Hardware Wizard.

If that fails,
Check the battery polarity. (+ and - must be in correct psoition)
Set the hold button to the unlock position.
Check if the file system is NTFS. If yes ,format it to FAT or FAT32. - Connect player to computer, click my computer, right click on icon of mp3 player and select format
If that fails,
go to www.mymusix.com to see if the latest software update will correct the problem
-Tha Mp3 Doctor