If you have SD card compatibility issue on 3DS, try to use M3GUpdaterPlus_142.nds to upgrade with compatible SD card or on NDS/NDSi to complete.
(For M3i Zero GMP-Z003 only)
Firmware Update: (For M3i Zero GMP-Z003 Only)
M3i Zero GMP-Z003 firmware Update
*Update the firmware of M3i Zero card...