That's what I did.The .CIA installation was the better way to do it, try that if you didn't already.
Oh, so without any of the cores, it won't run. But where do I even get cores?Which steps did you take to install retroarch?
To me it looks like you only installed 'retroarch_3ds.cia'. Which does nothing on it's own. (as shown in your video)
The actual cores are included in the 'retroarch/cores' folder. Did you copy that as-well?
It really isn't that difficult; https://docs.libretro.com/guides/install-3ds2ds/
Have tried both for a long while now and 3dsx running thru homebrew channel is the better way to go for sure.I tried both versions of Retroarch. And even downloaded all the cores that I needed. However, both versions of Retroarch, the 3dsx and cia, both crash on my new 3ds xl.