So I've had the card for quite some time already and it's been working fine for the most part. Lent my DSi to my gf and she's been using it this year or so. However, yesterday, as she was playing Mario & Luigi: BiS, the game froze, and when she restarted it gave her the system file is missing prompt. Searched a bit, and most threads were about not putting the correct installation files the right way, so I figured I'd make a thread. I also saw that the sd might be corrupted and that I should reformat it. Any tips or guesses as to why this could've happened? It's not an old fw either, not sure if the newest but I did update it to fix BiS freezing issues and used to keep up to date regarding major releases.