need r4ds sdhc file help

so i was playing it fine and everything for like 2 months and then i try to play it today and..stuck at loading screen so i put the micro sdhc in my computer to check the files and they are all messed up + i cant delete themi re-added all of my old files and they work fine but when i use it in the ds there are still the messed up files and i cant delete them from the cardi lost all my game info and id really like some help figuring this out

means the file names are using a different character set to your computer.

i kinda figuredthe problem ishow did it get changed and how do i fix them or delete them

usual method would be to back up your saves/roms (if they're intact) and then format the microsd, reinstall the firmware and put the backups back on.