/!\ Help with DS R4

[Neslug]

my girlfriend was using animati and colors on her DS, saved a file

Most likely, an error in properly saving the data caused the card's contents to corrupt.

I think this is most likely because the folders (and possibly the files inside) are corrupted and contain garbled characters in their filenames. This has actually happened to me before and I still haven't managed to delete the files (they're still on my portable hard drive but I just ignore them). It's probably best to format, like Viper said, as the only other thing you can do is...store other data on the card. If the contents are really corrupted like I am assuming, there's not really anything to lose anymore.