DJ Player Professional funktioniert nicht

DJ Player Pro supports all USB Class Compliant MIDI controllers and audio devices.  DJ Player Pro goes beyond the laptop DJ with superior audio quality, innovative control and style.  Safe storage and instant access for your cue points, loops and bpm data in the DJ Player Pro Cloud.  This unprecedented level of integration allows DJ Player Pro to provide better performance than laptop DJ software.  DJ Player Pro is designed for professional DJs that perform in clubs and on stage.  Use it standalone, or in any combination of the touchscreen, external mixers, MIDI controllers, sound cards and vinyl (DVS).  DJ Player Pro also outperforms all the over-priced, shiny gear you see at music festivals.  DJ Player Pro supports most timecode vinyl formats.  Instant track preparation with Cloud Community Power: if a new song has been prepared by fellow DJs, you get it prepared out-of-the-box.  Unlike other mobile DJ apps, displaying, sorting, searching and filtering happens within a fraction of a second, regardless of the size of your music library.  DJ Player Pro is the most flexible DJ solution.  Use a USB hub and multiple devices to create your wildest MIDI setup.  Extend your scratching techniques with DVS FX, MIDI-mappable multi-deck control or fixed 4 beats rotation.  Set your preference in DJ Player Pro.  Go crazy with individual effect routing. 4 decks with 4 Stems each -- 16 tracks simultaneously under your control.  "… the most legitimate consideration available for using an iPad (or iPads) to DJ instead of a laptop".