Please read the whole guide first and especially the FAQ and Beginner's Advice section at the end! Many questions that pop up again and again are already answered there.
Downgraded and homebrew / FBI not working?
If you used the new downgrade methodes and you can't seem to run any homebrew (crashes with black screen) or FBI gives you signature errors despite you doing everything right,...
[Tutorial] Setting up 9.0 - 9.2 N3DS/XL for CFW, including 10.3 EmuNAND, Coldboot, CIA Installer
Downgraded and homebrew / FBI not working?
If you used the new downgrade methodes and you can't seem to run any homebrew (crashes with black screen) or FBI gives you signature errors despite you doing everything right,...
[Tutorial] Setting up 9.0 - 9.2 N3DS/XL for CFW, including 10.3 EmuNAND, Coldboot, CIA Installer