Recently I purchased and installed a Gateway 3DS onto my Nintendo 3DS XL. Everything went smoothly, and I was/am able to play backup roms. However, I have a small issue with my MicroSD card; every time I plug my MicroSD card into my computer, it says the disk is unreadable. I can still play the game that was loaded onto the MicroSD card, but I cannot transfer over the save file or any data, and if I want to put a new game on it, it must be erased and formatted. For what it's worth, I formatted the MicroSD to MS-DOS (FAT), using Disk Utility on a Mac. I then proceeded to flash the rom over using GW3DS SD Imager. Every time after I do this, the card becomes unreadable to my Mac, however the game is still playable on the 3DS. What am I doing wrong, and how can I fix this issue? Thank you in advance for the advice.