I formated my 3ds system memory by mistake, then I lost the save data of ditigal games downloaded from eshop. Before I formated it, I backuped the nand.bin and all the files of sdcard to PC. I can find the *.sav. but when I copy the sav to 3ds after I redownloaded games from eshop, it came out with 'Save data Error'. I tried using SDF(SAVeFL), and found it seems that I should use it to backup the savedata before formating. Is there any way to restore .sav after formating system memory? Or should I restore the NAND and use SDF to backup the savedata?