[help] How do I enable cheats on nDS, Cores (melon/desmume)?

How do I enable cheats on nDS, Cores (melon/desmume)? I updated the cheat file, selected the directory, enabled the cheat and then activated it. I Also tried restarting the core and starting a new game, but nothing. Please help!

(if it matters, I tried the cheats from the retroarch repository for rune factory 2 usa)