Slashin-it-up

Y'all really need to read. Obviously you didnt follow the directions. Soundhax only supports 11.3 - 9.0

This is due to you being on 11.4.

You've probably used a cart update from stock firmware (1.0 or similar)(because of the -0), and so the Sound App has never been updated. It would be on the 1st...

You maybe using the wrong m4a file. (Sound file)

This is because UDSploit and Fasthax have different ways of entering. Also, UDSploit was never made to work with less then 11.3 because Fasthax work perfectly fine.