I know this is from 6 years ago, but here's what I did to fix my friend's N3DSXL with the same issue: Firstly, I held: L trigger, R trigger, D-Pad down, and A. I then turned it on (while still holding that button combo) to boot into safe mode, where the 3ds system can be repaired from a failed update, or to even just update the system. After updating the system, this then brought me to a touch screen displaying "An error has occured" upon booting up the console. To fix this, take out the battery for a few minutes, then re-insert (discharging the battery is not necessary). After doing these two things, the N3DSXL will have been fixed, and have booted to the home screen. Hope this helps anyone in the future!