A. Follow the following steps to fix the issue:
1. Copy all the card's contents in your computer (Very important if you do not follow this step, the card's contents will be lost when you proceed with the following steps)
2. Insert the card in your 3DX unit
3. Press on the notification that comes up saying SD card detected "Tap to fix ".
4. Set it up as a portable storage. (This step will format the card). Ensure that you have copied the cards contents before this step!
5. Insert the card in your computer again.
6. Create a folder in the SD card with the name "raster". ( Unless you copied the whole raster folder in the first step, in that case skip this step)
7. Copy all the card's content that you copied in first step back onto the card.
8. Now insert the SD card in your 3DX unit and follow the instructions that came with the letter to activate the maps.