Can't make anything out of that sentence, but I think there's a few things I can understand
1. Maybe the word "alone" means "by itself" since I can't think another possibility now, can you?
2. Maybe s/he means the files in her/his microSD changed, about which file, I don't know, which lead us to a few possibilities:
a. ROM names changed, a major issue, since when a microSD has the capability of auto-rewrite? This might render .sav files useless. I don't know what is the cause though
b. the .sav files renamed, same as above.
c. Some other not-important files likepictures or something got renamed, not important of course, but such an issue is a problem, what could be the cause?
Of all possibilities, can anybody provide a logical answer? I can't think of any right now