Alright, I've been stuck on this for like a week now so I figure it's about time I ask for help with this. I'm sure I'm just missing something obvious, but here goes!
I followed
this guide to downgrade my 3DS and set up EmuNAND and all that fun stuff, and it seemed to be working just fine until I tried to install a CIA file through FBI. All of my games and icons and such disappeared, but they can still be run through the Homebrew Launcher. Every time I try to install another CIA file it gives me an error (It says "SUMMARY_INVALID_ARGUMENT (0x7)" and the description is <unknown> (0x1)). I restored a backup of the emuNAND I made after I first got it working and the apps still work the first time you launch something, but then everything disappears again the next time I go back to the home menu.
Also, I'm not sure if this is related or not, but trying to access the EShop gives me a 007-0200 error and I've been trying to figure that out as well. It was giving me this error before the update today, but if I update and try to get into the shop it doesn't fix anything. I tried switching everything over to a different SD card, but that didn't help anything.
So, right now I have FBI injected into the Health and Safety app since the icon for the CIA of it I installed also disappeared, but I still can't seem to do anything with it. I'm on a New 3DS with 9.2 sysNAND with 10.3 emuNAND using ReiNAND. Can anyone help me out?