I see your 3ds is an old one. Smash takes a couple minutes to start up on the old3ds. Have you simply tried waiting a bit for it to start? Are you using an actual game cartridge or something like a gateway?
Hum yes, I've try with ReiNAND, AuReiNAND and CakesFW witht their last version...
Note: I use SaltySD Custom Update 1.1.5... And with any updates (so with Hans), this work, but I need the update to play correctly...
Are you using them with arm9loaderhax? Sometimes there is an issue when using those and a boot manager or anim9, try to disable any of those if you have either.