When the Sound Control Panel is set to Digidesign (instead of Built-In) other programs are able to use the Mbox for audio playback. Digidesign hardware is designed to allow only one program to use it at a time, therefore a conflict can occur if Pro Tools LE is launched while another application is using the Mbox (even the Mac OS can take control of the hardware).- Setting the Sound Control Panel to Built-In and restarting the computer should resolve this error.- If "Digidesign" is chosen as the output selection for another application, such as the software synth "Reason", Pro Tools LE won't launch and gives the -6009 error. You make any application that had been using Mbox hardware releases it's hold by choosing something other than "Digidesign" as it/s output selection. Example: Launch "Reason" and change the output of the synth from the "Digidesign" choice to something else.