I tried to start from retroarch.cia but always black back to the home menu. the core cia fies are fine.
try this
make sure to copy the retroarch folder in the .7z archive to the root of your SD, and check if "Core Dir" and "Core Info Dir" point to the correct folders (retroarch/cores and retroarch/cores/info respectively, you can also move them somewhere else if you want ofc).
if you don't want to install all cores, delete the corresponding .core files in the "Core Dir".












