I'll look into this, however you cannot use iPad layouts on iPhone and iPod touch. You can load them, but the controls will be constrained to the page, so they'll get smashed together. I'll probably provide a fix for that at some point in the future. However, if you are running MIDI Designer Lite and it's not "unlocked," that could also be the source of the problem. However, it should warn and not crash under any circumstance.
I'll look into this and get back here.