Hacking Gateway on old 3DS ran Smash fine previously, now on latest version no such luck

[Quincy]

This is right. Just remember when you leave settings it will go back to NAND not emuNAND. So don't accidentally exit settings, go back in, and then update because they will update your NAND. Make sure it says GW3D and then update straight away.

Hence the "Power off your 3DS" step. If you power it off first and folow that step by step, there's 0 chance of it going wrong

 

[GolyBidoof]

I was able to run Smash Bros 3DS just fine before updating recently on my old 3DS, now that I am on the 3DS XL downgraded running the latest firmware, every time I try to boot the game, I get a black screen and have to do a hard reset. Google told me my SD card needed at least 1.5GB free (the one in the 3DS itself) which I have made sure is the case, but that hasn't helped at all. Any idea what else might be making this not function properly?

Could the CIA of 1.4 update I installed be the issue?

No, that's not it. Funny enough, it started to happen to me too. I updated my SysNAND to 8.1 with retail Persona Q cartridge, updated Gateway to 3.02 (the one that's 'supposed' to speed up Micro SD reading speed) and since then I cannot boot Smash or Monster Hunter 4G (Ultimate, including demo) on emuNAND. Why? :/