If your PlayStation Vita can't see that you've inserted a PlayStation Vita game card, try turning the system off by pressing and holding the power button for two seconds and then tapping "Power Off". Remove the Game Card and make sure that it has been inserted correctly before re-inserting it and turning on the system.
If you are still experiencing issues, it's possible that the game card is faulty, so if you can, try starting a different game card on your system. If you're having the same problem with more than one game card, your PlayStation Vita might not be working properly. If this is the case please contact PlayStation Support.
If you would like to continue playing your game from your Saved Data on a different system, you will need to insert your memory card as well and link your SEN account to that device. Find out more about sharing your memory card with another PlayStation Vita system.
Likewise, if you would like to continue earning trophies on your profile when using a different PlayStation Vita system, you will need to make sure that your account is linked to that device.