I think I am, since the guide I was using specifically mentioned the N3DS.
But just to try everything I exchanged my "updates" folder on the SD card for another "updates" derived from 9.2.0-20J(Full)_n3DS.zip, on https://mega.nz/#F!IApGwLJL!kYHL5jMlDfd0rmn6a8DaFw
This led to this error...