So, one time all of my 3DS themes (that I bought from the theme shop) randomly disappeared from my 3DS. And every time I try accessing the theme shop, I get an error. Today I tried installing a theme with CHMM and it seemed to work fine. Then I closed my 3DS and put it down for a while. And when I opened it back up, it was frozen. I forced it to turn off. But then it wouldn't turn on again. So I removed the SD card so I could get it to turn on.