Chosen Solution
Basically, I got a N2DS today and forgot to transfer my N3ds files to it. No big deal, it’s whatever. I tried linking my Nintendo ID to the 2ds, but it said it was already linked to a 3ds. I tried system transferring my 3ds to 2ds, but, it told me to system update. Alright, I do a system update but the moment it finished, Homebrew popped up and it says “An error has occurred: failed to apply 1 FIRM patch(es). Press any button to shutdown.” Everytime I push down a button, the same message shows up and it stays on the black screen. I’m not tech savvy at all and all my guy friends did all the modding for me.
Homebrewing is not available on the newer firmware releases on the 3DS/2DS. When you updated your 2DS to transfer the files, Homebrewing is not available and hence the error. To still use homebrew you need to flash older firmware on your device. There are many tutorials on youtube. There may soon be a newer homebrew method for the new firmware but that is unavailable at the moment.
