I HAD BEEN SUCCESSFULLY DRAGGING AND DROPPING MIDI CLIPS FROM THE TRACK VIEW TO THE MATRIX CELLS WITH NO PROBLEM, BUT MY MATRIX CELLS NO LONGER ARE WORKING-WHENEVER I TRIGGER THEM THEY NO LONGER PLAYBACK. I LOOKED IN THE HELP CONTENT AND CANT FIND ANYTHING THAT I MIGHT HAVE ACCIDENTALLY DISABLED, BUT CANT FIND ANYTHING. I HAVE ATTEMPTED TO CREATE NEW PROJECTS CREATING NEW TRACKS, BUT STILL HAVE NO SUCCESS; THE CELLS ARE PLAYING BACK, BUT I DONT HEAR ANYTHING. THE CLIPS PLAYBACK FINE IN THE TRACK VIEW BUT NOT THE MATRIX CELLS. HAS THIS HAPPENED TO ANYONE ELSE?