Topic: Some data corruption/loss after SD card switch

In order to download Shadows of Valentia I bought a new, bigger SD card. My coworker, who has done file transfers with his own 3DS SD cards, copied the data over for me.

It worked perfectly, except:
Every time I try to open Pokemon Picross or the Streepass Plaza, it tells me to turn the power off and restart (which does nothing, keeps telling me to restart with a blank black screen)

I checked through the data and noticed that there’s three files that just have “?” on them, and there’s no data for Pokemon Picross, Streetpass Plaza, or Fire Emblem Fates (the only DLC I have for that it bonus maps like Ghostly Gold, not an actual game path)

I checked similar threads and tried reinserting the original SD card and starting each game, then switching back, but it hasn't made a difference.

I tried starting Fates and it gave me a message about how the data had been corrupted and had to be recreated.

I'm not too broken up about the loss - I seem to still have the actual save files for Fates - but I'm not sure how to fix this, especially the Plaza. And when trying to load a Fates save file, it asks if I want to start with part of the save data removed, which I'm guessing... I do not.

Also I have no idea if any of the tags I tried to use here stuck -_-