Just for information (if it can help some peoples), I updated three 3DS (N3DS XL, N3DS and a 2DS), which were using Gateway, to bs9/luma and noticed soundhax never wanted to work on the 2DS (9.2). Each time, it would crash with the "an error has occured" message.
So if someone have the same problem, try to use browserhax (
https://yls8.mtheall.com/3dsbrowserhax.php). That's what I did to launch the homebrew launcher and it worked fine.
The guide is very good by the way, enough to made me want to send a donation to his author through Paypal, he deserved it.