You can't just move apps to a SD card, so that is probably part of your problem. Now the card can be defective, new or not. It happens. There also can be a problem with your devices slot where the card is inserted. If the phone will recognize the card when inserted, then it is working fine. There is also the possibility that the card you have isn't right for your device. If it is the wrong type or has a larger capacity than the phone allows.