I was intrigued by this new function added in the newest system update, the one that allows us to save and load customized layouts of the Home menu rather than just slapping a new skin on the exixting one. The first time I entered the menu I was able to save the layout I had prior to the update. I then went and changed the size & layout of the icons, but when I tried to go back to the "Save/Load Layout" menu it just froze. It didn't transition to the functions menu, the HUD on the upper screen vanished, the controls became unresponsive, and the theme's music stopped, reverting to the original Home menu's abient music. The only way I was able to get the system unfroze was by holding the power button, which brought up the "Sleep Mode" blank screen, giving me the option of returning to the Home Menu or powering the system off.
I tried everything to get this to work: simply returning to the Home Menu, powering the system off and on again, changing the Theme before accessing the Layout Menu, even attempting to update the system again, all to no avail. Maybe the New 3DS XL systems have no problem with this functionality, but it currently doesn't work on my regular 3DS XL. Hope you can get this fixed soon.