Double-check that your save folder ID matches your game ISO ID.

If you want to transfer your save data to another PSP, copy the backup folder from your computer onto the second PSP's PSP/SAVEDATA folder. As long as the game region (e.g., USA, Europe, Japan) is the same, the save should be compatible.

To back up your save data to your computer:

: /PSP/SAVEDATA/ (usually in the root of your internal storage). PC : [PPSSPP Folder]/memstick/PSP/SAVEDATA/ .

Path for older Android versions: Internal Storage/PSP/SAVEDATA/