What is the make and model number of the nav system please?
Did it work ok previously, or are you setting it up for the first time?
Can you enter all of the other app icons ok?
Did it work ok previously. Other app icons its ok. After factory restore the map doesn"t work.
Ok, can you try another factory restore and let me know if that works?If it still doesn't work, do you have a backup of the original files?