Gurren

Good day everyone, I'm new to the Launchbox scene so please bare with me. I was watching the video on how to import Nintendo GBA games with Retroarch. Afterwards I followed the steps and completely imported the all the GBA games onto Launchbox but when I go to start a game up it does nothing. So I deleted the file and started importing it again in case I messed up somewhere but yet again the games will not start. Can someone please help me correct this problem I'm having?