The script may not output a seeddb.bin , or it may display an error when trying to dump it. This simply indicates that your console does not have any seeds and thus you should not need them. If this happens you can ignore the error.
To work correctly, the file must be named exactly aes_keys.txt and placed in the sysdata folder of your Citra user directory. Typical Path C:\Users\[YourName]\AppData\Roaming\Citra\sysdata Linux/macOS citra aes keystxt work
He pasted the aes_keys.txt file into the folder. The script may not output a seeddb
If you are playing a very new game or a game that was updated using a later firmware version, you may need a newer, updated aes_keys.txt . you may need a newer