If the game attempts to boot but fails immediately with a black screen, your AES keys file may be missing a specific key slot required for that particular game generation, or the ROM file itself might be corrupted. Re-dumping the game using GodMode9 as a decrypted .3ds file is a reliable workaround if encryption keys continue to cause issues.
Because these keys are proprietary property of Nintendo, they are not legally bundled with the emulator and should be dumped from your own hardware. Dumping Keys : Most users use a GodMode9 script (typically dumpkeys.gm9 citra aes keystxt high quality
C:\Users\[YourUsername]\AppData\Roaming\Citra\sysdata\ Linux: ~/.local/share/citra-emu/sysdata/ macOS: ~/Library/Application Support/Citra/sysdata/ If the game attempts to boot but fails