How to utilize the 3DS MICROSD MANAGEMENT to transfer files wirelessly - YouTube
I updated to 11.16. Don't know if that was a good idea but streetpass didn't so I updated. Never had this problem. does someone know what happened? (I have custom firmware) :
How to fix Micro SD Management 3ds (Cannot access// error) - YouTube
3DS SD Card Format | How to Format SD Card for 3DS
Abacus24-7 Nintendo Switch Memory Card, 32 GB microSD with SD Adapter, also for 2DS, 3DS, 3DS XL, Wii & Wii U - Walmart.com