new e class amp line media player problem

[macthedj]

Hi can someone help me. My boss has just purchased a new e class amp line. This is used as his taxi business and so he needs the media player to play movies during quiet times. Now I have tried a new SanDisk 128 go usb stick with movies and music on it but the problem is the car keeps saying device not recognised. Does anyone know if the usb needs some software added or if there is only certain usb sticks that will work.