Starting around system firmware 9.6, Nintendo implemented an extra layer of security for certain 3DS games. In addition to the standard encryption keys, these games require a console-unique or title-specific "seed" to be fully decrypted. Common Use Cases You will typically run into the need for a seeddb.bin file in the following scenarios: Custom-Install (PC-to-SD Installation):

use it to prepare games on a PC before transferring them to an SD card. How to Get and Use It seeddb.bin

Once installed, those "corrupted" games should boot instantly.